Service executing apparatus

ABSTRACT

A broadcast receiving terminal, which implements a service executing method, includes a receiver operable to receive an application, a recording medium, and a service executer operable to execute a service that uses one or more resources in a service execution environment intended for the service. The terminal also includes an associater operable to associate the service execution environment with resource set information indicating the one or more resources used by the service, when the application requests the service executer to execute the service, and a storager operable to store, into the recording medium, a plurality of service execution environments together with the associated resource set information that are associated by the associater. The terminal further includes a resource manager operable to provide, to a selected service, one or more resources indicated in the resource set information in the associated service execution environment, in the recording medium, stored by the storager.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of pending U.S. patent applicationSer. No. 10/910,748, filed Aug. 4, 2004, which claims the benefit of60/547,767, filed Feb. 27, 2004, which claims priority of JapaneseApplication No. 2003-287626, filed Sep. 6, 2003, the contents of whichare expressly incorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a digital television, and particularlyto a terminal that is equipped with a plurality of processing devicessuch as video recorder.

(2) Description of the Related Art

On the hardware of a broadcasting receiving apparatus represented by atelevision and a STB, a plurality of devices with different functionsare interconnected so that an output from one device serves as an inputto another device. By forming a series of flows in the above manner, aplurality of devices provide a great functionality on the hardware. Forexample, when video and audio are outputted to the screen of a digitalbroadcasting receiving apparatus, the following devices are connected onthe hardware in order of mention, so that video and the like isdisplayed on the screen and audio is outputted by such devicesperforming the respective functions: a “tuner” that receives anbroadcast signal as an input, performs filtering on such broadcastsignal using the frequency as a key, and outputs an MPEG2 (MotionPicture Expert Group-2) transport stream; a “TS decoder” that receivesthe MPEG2 transport stream as an input, selects desired video/audio anddata from it, and outputs video/audio data or data to be carried by TSpackets corresponding to the selected video/audio data or data; an“audio decoder” and a “video decoder” that decode the video/audio datatransmitted from the TS decoder and output it in a form that can bedisplayed on the screen; and a “display device” that synthesizes videoand others indicated by the “video decoder” or the CPU.

In some cases, a broadcasting receiving apparatus such as above isequipped with more than one device of the same type. For example, whenthere are a plurality of “tuners” and “video decoders”, it is possibleto decode more than one piece of video data concurrently and thereforeto achieve a function, known as “Picture In Picture (hereinafterreferred to as PinP)”, for displaying two types of video dataconcurrently, for example. In the case such as above where a pluralityof devices of the same type exist, which “tuner” and which “videodecoder” are to be interconnected cannot be determined freely.Therefore, it is usually determined beforehand that a specified “tuner”and a specified “video decoder” should be interconnected, and a seriesof devices are handled in “sets”. As a representative example method ofusing each device in such a case, a technique disclosed in “JapaneseLaid-Open Patent application No. 8-289220” is introduced here. In thisinvention, two sets of a “main tuner”, a “main video decoder”, an“insertion tuner” and an “insertion decoder” are used, and in the caseof PinP display, the use of the “insertion tuner” makes it possible forthe video and audio of a candidate selection to be displayed on aspecified area on the screen, with an already-selected video and audioremaining displayed on the screen in full size.

In Europe, a specification known as “DVB-MHP (Digital VideoBroadcasting-Multimedia Home Platform ETSI TS101 812 V1.2.1 (2002-06))for executing services on broadcasting receiving apparatus is definedand in operation. Meanwhile, in the United Sates, a specification called“OCAP (OpenCable Application Protocol OCAP1.0 ProfileOC-SP-OCAP1.0-107-030522) is under development on the basis of theDVB-MHP specification and scheduled to be brought into operation withinthe year 2005. Furthermore, similar specifications are under developmentor in operation in various countries. Broadcasting receiving apparatusescompliant with these specifications on service execution are capable ofexecuting programs that are obtained from broadcast signals by means ofdownload and the like. Representative examples of the programs includegame and EPG (Electronic Program Guide) application.

As a service to be executed on a broadcasting receiving apparatus, it isnatural to conceive an application for displaying more than one piece ofaudio and video data concurrently on one screen such as theaforementioned PinP and enhanced EPG. In order to output plural piecesof video and audio data concurrently on one screen, it is necessary tocontrol sets of plural devices, as represented by the above-describedpatent. However, the DVB-MHP/OCAP specifications do not providedescriptions about the configuration for controlling sets of pluraldevices.

SUMMARY OF THE INVENTION

In view of the above, the present invention aims at providing a serviceexecuting apparatus that controls a “set” of plural devices, byemploying a concept of identifying a “set” of plural devices by aServiceContext class, and also providing a mechanism for using a “set”of devices that is identified by another ServiceContext class.

In order to achieve the above object, the service executing apparatusaccording to the present invention is a service executing apparatuscomprising: a service executing unit operable to execute a service thatuses one or more resources in a service execution environment intendedfor said service; an associating unit operable to associate the serviceexecution environment with resource set information indicating said oneor more resources used by the service, when an application requests theservice executing unit to execute the service; a holding unit operableto hold the service execution environment and the resource setinformation that are associated by the associating unit; and a resourcemanaging unit operable to provide, to the service, the resource setinformation held by the holding unit in the service executionenvironment held by the holding unit.

Accordingly, since a ServiceContext that is a service executionenvironment is associated with resource set information indicating oneor more resources used by the service, it is possible to control one ormore resources as a “set” of resources at the time of service execution.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages and features of the invention willbecome apparent from the following description thereof taken inconjunction with the accompanying drawings that illustrate a specificembodiment of the invention. In the drawings:

FIG. 1 is a diagram showing a structure of a cable television systemaccording to a first embodiment of the present invention;

FIG. 2 is a diagram showing an example of using frequency bands to beused for communications between a head end and terminal apparatuses inthe cable television system according to the present invention;

FIG. 3 is a diagram showing an example of using frequency bands to beused for communications between the head end and the terminalapparatuses in the cable television system according to the presentinvention;

FIG. 4 is a diagram showing an example of using frequency bands to beused for communications between the head end and the terminalapparatuses in the cable television system according to the presentinvention;

FIG. 5 is a diagram showing a configuration of a terminal apparatus inthe cable television system according to the present invention;

FIG. 6 is a diagram showing an example external view of the terminalapparatus in the cable television system according to the presentinvention;

FIG. 7 is a diagram showing a hardware configuration of a POD 504according to the present invention;

FIG. 8 is a diagram showing an example of a display window displayed bya display 509 according to the present invention;

FIG. 9 is a diagram showing an example of a display window displayed bythe display 509 according to the present invention;

FIG. 10 is a diagram showing a structure of a program stored in the POD504 according to the present invention;

FIG. 11A is a diagram showing a configuration of a TS decoder Aaccording to the present invention;

FIG. 11B is a diagram showing a configuration of a TS decoder Baccording to the present invention;

FIG. 12 is a diagram showing a structure of a packet defined in the MPEGstandard;

FIG. 13 is a diagram showing an example of an MPEG2 transport stream;

FIG. 14 is a diagram showing an example external view of an input unit513 in the case where it is configured in the form of a front panel;

FIG. 15 is a diagram showing a configuration of a display device A520 aor a display device B520 b according to the present invention;

FIG. 16 is a diagram showing a configuration of a display deviceaccording to the present invention;

FIG. 17 is a diagram showing a structure of the program stored in theterminal apparatus 500 according to the present invention;

FIG. 18 is a diagram showing an example of information stored in asecondary storage unit 510 according to the present invention;

FIG. 19A is a diagram showing an example of information stored in aprimary storage unit 511 according to the present invention;

FIG. 19B is a diagram showing another example of information stored in aprimary storage unit 511 according to the present invention;

FIG. 19C is a diagram showing further another example of informationstored in a primary storage unit 511 according to the present invention;

FIG. 20 is a diagram showing a configuration of a service manager 1704according to the present invention;

FIG. 21 is a diagram showing an example of a ServiceContext managementunit according to the present invention;

FIG. 22 is a diagram showing an example of a ServiceContext for In-bandservice according to the present invention;

FIG. 23 is a diagram showing an example of a resource set holding unitaccording to the present invention;

FIG. 24 is a diagram showing an example of sets of resources accordingto the present invention;

FIG. 25 is a flowchart relating to the obtainment of ServiceContextsaccording to the present invention;

FIG. 26 is a diagram showing a relationship between the ServiceContextsand the set of resources according to the present invention;

FIG. 27 is a flowchart for obtaining an instance of a Java classrepresenting a tuner according to the present invention;

FIG. 28 is a flowchart for obtaining an instance of a Java class thatreproduces video and audio according to the present invention;

FIG. 29 is a schematic diagram showing the contents of a PAT specifiedin the MPEG2 standard according to the present invention;

FIG. 30 is a schematic diagram showing the contents of a PMT specifiedin the MPEG2 standard according to the present invention;

FIG. 31 is a schematic diagram showing the contents of an AIT specifiedin the DVB-MHP standard according to the present invention;

FIG. 32 is a schematic diagram showing a file system to be transmittedin the DSMCC format according to the present invention;

FIG. 33 is a diagram showing an example of a display window displayed bythe display 509 according to the present invention;

FIG. 34 is a diagram showing an example of a display window displayed bythe display 509 according to the present invention;

FIG. 35 is a diagram showing an example of a display window displayed bythe display 509 according to the present invention;

FIG. 36 is a diagram showing an example of a display window displayed bythe display 509 according to the present invention;

FIG. 37 is a diagram showing an example of a display window displayed bythe display 509 according to the present invention;

FIG. 38 is a diagram showing an example of a display window displayed bythe display 509 according to the present invention;

FIG. 39 is a diagram showing a configuration of a ServiceContext forAbstract service according to the present invention;

FIG. 40A is a diagram showing an example display window displayed by thedisplay 509 according to the present invention;

FIG. 40B is a diagram showing another example display window displayedby the display 509 according to the present invention;

FIG. 41 is a schematic diagram showing the contents of XAIT according tothe present invention;

FIG. 42 is a diagram showing an example of information stored in thesecondary storage unit 510 according to the present invention;

FIG. 43 is a diagram showing a relationship between the ServiceContextsand the sets of resources according to the present invention;

FIG. 44 is a diagram showing a Java class according to the presentinvention;

FIG. 45 is a flowchart for reproducing video and audio according to thepresent invention;

FIG. 46 is a flowchart for reproducing video and audio according to thepresent invention;

FIG. 47 is a diagram showing a configuration of a ServiceContext forAbstract service;

FIG. 48 is a diagram showing a configuration of the ServiceContext forAbstract service;

FIG. 49 is a diagram showing a Java class according to the presentinvention;

FIG. 50 is a flowchart for reproducing video and audio according to thepresent invention;

FIG. 51 is a diagram showing a configuration of the service manager 1704according to the present invention;

FIG. 52 is a diagram showing a configuration of a ServiceContext mappingunit according to the present invention;

FIG. 53 is a diagram showing an example of a ServiceContext mappingholding unit according to the present invention;

FIG. 54 is a diagram showing a Java class according to the presentinvention;

FIG. 55 is a flowchart for reproducing video and audio according to thepresent invention;

FIG. 56 is a diagram showing a configuration of the ServiceContext forAbstract service;

FIG. 57 is a diagram showing a configuration of the ServiceContext forAbstract service;

FIG. 58 is a diagram showing a Java class according to the presentinvention;

FIG. 59 is a flowchart for obtaining an instance of a Java class thatreproduces video and audio according to the present invention.

FIG. 60 is a flowchart for reproducing video and audio according to thepresent invention;

FIG. 61 is a diagram showing a Java class according to the presentinvention;

FIG. 62 is a flowchart for obtaining an instance of a Java class thatreproduces video and audio according to the present invention;

FIG. 63 is a diagram showing a configuration of the service manager 1704according to the present invention;

FIG. 64 is a diagram showing a configuration of aServiceContext-resource set mapping unit according to the presentinvention;

FIG. 65 is a diagram showing an example of a resource set holding unitaccording to the present invention;

FIG. 66 is a diagram showing a Java class according to the presentinvention;

FIG. 67 is a flowchart for reproducing video and audio according to thepresent invention;

FIG. 68 is a diagram showing a configuration of the service manager 1704according to the present invention;

FIG. 69 is a diagram showing a configuration of aServiceContext-resource mapping unit according to the present invention;

FIG. 70 is a diagram showing an example of a resource holding unitaccording to the present invention;

FIG. 71 is a diagram showing a Java class according to the presentinvention;

FIG. 72 is a flowchart for reproducing video and audio according to thepresent invention;

FIG. 73 is a diagram showing a configuration of a Java library 1705according to the present invention;

FIG. 74 is a diagram showing a relationship between Java classes andphysical resources according to the present invention;

FIG. 75 is a diagram showing an example of a display window displayed bythe display 509 according to the present invention;

FIG. 76 is a diagram showing a Java class according to the presentinvention;

FIG. 77 is a diagram showing a Java class according to the presentinvention;

FIG. 78 is a diagram showing a configuration of a display deviceaccording to the present invention;

FIG. 79 is a diagram showing a Java class according to the presentinvention;

FIG. 80 is a diagram showing a Java class according to the presentinvention; and

FIG. 81 is a diagram showing an EPG according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following describes the preferred embodiments of the presentinvention with reference to the drawings.

First Embodiment

A preferred embodiment of the cable television system according to thepresent invention is described with reference to the drawings. FIG. 1 isa block diagram showing the relationship among apparatuses composing thecable system, which are a head end 101 and three terminal apparatuses: aterminal apparatus A111, a terminal apparatus B112, and a terminalapparatus C113. In the present embodiment, three terminal apparatusesare connected to one head end, but it is possible to carry out thepresent invention if an arbitrary number of terminal apparatuses areconnected to the head end.

The head end 101 transmits, to plural terminal apparatuses, broadcastsignals such as video, audio and data, and receives data transmittedfrom the terminal apparatuses. In order to realize this, frequency bandsare divided for use of data transmission between the head end 101, andthe terminal apparatus A111, the terminal apparatus B112, and theterminal apparatus C113.

FIG. 2 is a table showing an example of divided frequency bands. Thereare roughly two types of frequency bands: Out of Band (to be abbreviatedas OOB) and In-Band. A frequency band of 5-130 MHz is allocated to OOBto be mainly used for data exchange between the head end 101, and theterminal apparatus A111, the terminal apparatus 8112, and the terminalapparatus C113. A frequency band of 130 MHz-864 MHz is allocated toIn-Band to be mainly used for broadcasting services including video andaudio. QPSK is employed for OOB, whereas QAM64 is employed for In-Bandas modulation techniques. A detailed explanation of the modulationtechniques is omitted here, since they are publicly known techniqueswhich are less related to the present invention.

FIG. 3 shows a more specific example of how the OOB frequency band isused. A frequency band of 70 MHz-74 MHz is used to transmit data fromthe head end 101. In this case, all of the terminal apparatus A111, theterminal apparatus B112, and the terminal apparatus C113 receive thesame data from the head end 101. Meanwhile, a frequency band of 10.0MHz-10.1 MHz is used to transmit data from the terminal apparatus A111to the head end 101. A frequency band of 10.1 MHz-10.2 MHz is used totransmit data from the terminal apparatus B112 to the head end 101. Afrequency band of 10.2 MHz-10.3 MHz is used to transmit data from theterminal apparatus C113 to the head end 101. Accordingly, it becomespossible to transmit data unique to each terminal apparatus to the headend 101 from the terminal apparatus A111, the terminal apparatus B112,and the terminal apparatus C113.

FIG. 4 shows an example use of the In-Band frequency band. Frequencybands of 150-156 MHz and 156-162 MHz are allocated respectively to atelevision channel 1 and a television channel 2, and the subsequentfrequencies are allocated to television channels at 6 MHz intervals. 310MHz and the subsequent frequencies are allocated to radio channels at 1MHz intervals. Each of the above channels may be used either for analogbroadcasting or digital broadcasting. In the case of digitalbroadcasting, data is transmitted in the transport packet formatcompliant with the MPEG2 specification, in which case data intended forvarious data broadcasting systems can be transmitted, in addition toaudio and video data.

The head end 101 is equipped with a QPSK modulation unit, a QAMmodulation unit, and the like in order to transmit broadcast signalssuitable to the respective frequency ranges. Moreover, the head end 101is equipped with a QPSK demodulation unit for receiving data from theterminal apparatuses. Also, the head end 101 is assumed to be furtherequipped with various devices related to the above modulation units anddemodulation unit. However, a detailed explanation of them is omittedhere, since the present invention is mainly related to the terminalapparatuses.

The terminal apparatus A111, the terminal apparatus B112, and theterminal apparatus C113 receive and reproduce broadcast signalstransmitted from the head end 101. Furthermore, the terminal apparatusA111, the terminal apparatus B112, and the terminal apparatus C113transmit data unique to each terminal apparatus to the head end 101.

In the present embodiment, these three terminal apparatuses are assumedto be terminal apparatuses capable of displaying two windowssimultaneously such as ones represented by Picture in Picture and DoubleWindow, for example. Note that the present invention is not limited totwo windows, and therefore it is possible to carry out the presentinvention if terminal apparatuses are capable of displaying an arbitrarynumber of windows simultaneously.

FIG. 5 is a block diagram showing a hardware configuration of eachterminal apparatus. 500 is a terminal apparatus, which is made up of atuner A501 a, a tuner B501 b, a QPSK demodulation unit 502, a QPSKmodulation unit 503, a TS decoder A505 a, a TS decoder B505 b, an audiodecoder A506 a, an audio decoder B506 b, a speaker 507, a video decoderA508 a, a video decoder B508 b, a display 509, a secondary storage unit510, a primary storage unit 511, a ROM 512, an input unit 513, a CPU514, a demultiplexer 515, a multiplexer 516, a display device A520 a,and a display device B520 b. Furthermore, a POD 504 can be attachedto/detached from the terminal apparatus 500.

FIG. 6 shows a thin-shaped television, which is an example external viewof the terminal apparatus 500.

601 is a steel case of the thin-shaped television, in which allcomponents of the terminal apparatus 500 except for the POD 504 arecontained.

602 is a display, which corresponds to the display 509 in FIG. 5.

603 is a front panel unit which is made up of plural buttons and whichcorresponds to the input unit 513 in FIG. 5.

604 is a signal input terminal to which a cable line is connected fortransmitting/receiving signals to and from the head end 101. The signalinput terminal is connected to the tuner A501 a, the tuner B501 b, theQPSK demodulation unit 502, and the QPSK modulation unit 503 shown inFIG. 5.

605 is a POD card corresponding to the POD 504 in FIG. 5. The POD 504 isembodied independently of the terminal apparatus 500 and can be attachedto/detached from the terminal apparatus 500, as in the case of the PODcard 605 in FIG. 6. A detailed explanation of the POD 504 is givenlater.

606 is an insertion slot into which the POD 605 is inserted.

The terminal apparatus shown in FIG. 5 is capable of full-screen displayas illustrated as a display window 801 in FIG. 8 and capable ofdisplaying two windows simultaneously as illustrated in FIG. 9. In FIG.9, the display 509 displays two windows, where the display window 801shows video and audio that is reproduced based on the resultant ofdemodulating, by the tuner A501 a, signals transmitted from the head end101 in FIG. 5, whereas a display window 901 shows video and audio thatis reproduced based on the resultant of demodulating, by the tuner B501b, signals transmitted from the head end 101 in FIG. 5.

Referring to FIG. 5, each of the tuner A501 a and tuner B501 bdemodulates a signal which has been QAM-modulated in and transmittedfrom the head end 101, according to tuning information that includes afrequency specified by the CPU 514, and passes the resultant to themultiplexer 516. The multiplexer 516 multiplexes it and passes theresultant to the POD 504.

The QPSK demodulation unit 502 demodulates a signal which has beenQPSK-modulated in and transmitted from the head end 101, according totuning information that includes a frequency specified by the CPU 514,and passes the resultant to the POD 504.

The QPSK modulation unit 503 QPSK-demodulates a signal passed from thePOD 504, according to demodulation information that includes a frequencyspecified by the CPU 514, and transmits the resultant to the head end101.

As shown in FIG. 6, the POD 504 is detachable from the main body of theterminal apparatus 500. The definition of the connection interfacebetween the main body of the terminal 500 and the POD 504 is given inOpenCable™ HOST-POD Interface Specification(OC-SP-HOSTPOD-IF-I12-030210) and in specifications referred to by suchspecification. Therefore, a detailed description is omitted here, and anexplanation is given only of constituent elements relevant to thepresent invention.

FIG. 7 is a block diagram showing an internal configuration of the POD504. The POD 504 is made up of a first descrambler unit 701, a seconddescrambler unit 702, a scrambler unit 703, a primary storage unit 704,a secondary storage unit 705, and a CPU 706.

Under the instruction from the CPU 706, the first descrambler unit 701receives, from the tuner A501 a and the tuner B501 b of the terminalapparatus 500, signals that are obtained by multiplexing scrambledsignals by the multiplexer 516, and descrambles such signals. Then, thefirst descrambler unit 701 transmits the descrambled signals to thedemultiplexer 515, which demultiplexes them and transmits the resultantto the TS decoder A505 a and the TS decoder B505 b of the terminalapparatus 500. Information required for decoding such as a key isprovided by the CPU 706 according to need. More specifically, the headend 101 broadcasts several pay channels, and when the user purchased theright to view these pay channels, the first descrambler unit 701receives required information such as a key from the CPU 706 andperforms descrambling. Accordingly, the user can view these paychannels. When required information such as a key is not provided, thefirst descrambler unit 701 passes the received signals directly to theTS decoder A505 a and the TS decoder B505 b via the demultiplexer 515,without performing descrambling.

The second descrambler unit 702 receives a scrambled signal from theQPSK demodulation unit 502 of the terminal apparatus 500 under theinstruction from the CPU 706, and descrambles such signal. Then, thesecond descrambler unit 702 passes the descrambled data to the CPU 706.

The scrambler unit 703 scrambles the data received from the CPU 706,under the instruction from the CPU 706, and sends the resultant to theQPSK modulation unit 503 of the terminal apparatus 500.

The primary storage unit 704, a concrete constituent element of which isa primary memory such as a RAM, is intended for storing data temporarilywhen the CPU 706 performs processing.

The secondary storage unit 705, a concrete constituent element of whichis a secondary storage memory such as a flash ROM, is intended forstoring a program to be executed by the CPU 706 as well as for storingdata which should never be deleted even when the power is turned off.

The CPU 706 executes the program stored in the secondary storage unit705. The program is made up of plural sub programs. FIG. 10 shows anexample of the program stored in the secondary storage unit 705. In FIG.10, a program 1000 is made up of plural sub programs including a mainprogram 1001, an initialization sub program 1002, a network sub program1003, a reproduction sub program 1004, and a PPV sub program 1005.

Here, PPV, which is an abbreviation of Pay Per View, refers to a servicethat allows the user to view a certain program such as a movie on achargeable basis. When the user enters his/her personal identificationnumber, the fact that the user purchased the right to view the programis notified to the head end 101, and the program is descrambled.Accordingly, the user can view such program. This viewing of the programrequires the user to pay for the purchase at later date.

The main program 1001, which is the sub program activated by the CPU 706first of all when the power is turned on, controls the other subprograms.

The initialization sub program 1002, which gets activated by the mainprogram 1001 when the power is turned on, carries out informationexchange and the like with the terminal apparatus 500 to performinitialization processing. This initialization processing is defined indetail in OpenCable™ HOST-POD Interface Specification(OC-SP-HOSTPOD-IF-I12-030210) and in specifications referred to by suchspecification. Furthermore, the initialization sub program 1002 alsoperforms initialization processing not defined in these specifications.Here, a part of such initialization processing is introduced. When thepower is turned on, the initialization sub program 1002 notifies theQPSK demodulation unit 502 of a first frequency stored in the secondarystorage unit 705 via the CPU 514 of the terminal apparatus 500. The QPSKdemodulation unit 502 performs tuning using the provided firstfrequency, and transmits the resulting signal to the secondary scramblerunit 702. Moreover, the initialization sub program 1002 provides thesecondary descrambler unit 702 with descrambling information such as afirst key stored in the secondary storage unit 705. As a result, thesecondary descrambler unit 702 performs descrambling and passes theresultant to the CPU 706 executing the initialization sub program 1002.Accordingly, the initialization sub program 1002 can receive theinformation. In the present embodiment, the initialization sub program1002 receives information via the network sub program 1003. A detaileddescription on this is given later.

Furthermore, the initialization sub program 1002 notifies the QPSKmodulation unit 503 of a second frequency stored in the secondarystorage unit 705 via the CPU 514 of the terminal apparatus 500. Theinitialization sub program 1002 provides the scrambler unit 703 withscrambling information stored in the secondary storage unit 705. Whenthe initialization sub program 1002 provides, via the network subprogram 1003, the scrambler unit 703 with information required to besent, the scrambler unit 703 scrambles the data using the providedscrambling information, and provides the scrambled data to the QPSKmodulation unit 503 of the terminal apparatus 500. The QPSK modulationunit 503 modulates the scrambled information which it received, andsends the modulated information to the head end 101.

As a result, it becomes possible for the initialization sub program 1002to carry out a bilateral communication with the head end 101 via theterminal apparatus 500, the secondary descrambler unit 702, thescrambler unit 703, and the network sub program 1003.

The network sub program 1003, which is used by plural sub programs suchas the main program 1001 and the initialization sub program 1002, is asub program intended for carrying out a bilateral communication with thehead end 101. More specifically, the network sub program 1003 behaves asif other sub programs using the network sub program 1003 were carryingout a bilateral communication with the head end 101 in accordance withTCP/IP. A detailed explanation of TCP/IP is omitted here, since it is apublicly known technique that specifies the protocols to be used whenexchanging information between plural terminals. When activated by theinitialization sub program 1002 at power-on time, the network subprogram 1003 notifies, via the terminal apparatus 500, the head end 101of an MAC address (an abbreviation of Media Access Control) which is anidentifier for identifying the POD 504 and which is stored in thesecondary storage unit 705 beforehand, so as to request for obtaining anIP address. The head end 101 notifies the POD 504 of the IP address viathe terminal apparatus 500, and the network sub program 1003 stores suchIP address into the primary storage unit 704. From then on, the head end101 and the POD 504 communicate with each other using such IP address asthe identifier of the POD 504.

The reproduction sub program 1004 provides the first descrambler unit701 with descrambling information such as a second key stored in thesecondary storage unit 705 as well as descrambling information such as athird key provided by the terminal apparatus 500, so as to allowdescrambling to be performed. Furthermore, the reproduction sub program1004 receives, via the network sub program 1003, information indicatingthat the signal inputted in the first descrambler unit 701 is a PPVchannel. On the notification that the signal is a PPV channel, thereproduction sub program 1004 activates the PPV sub program 1005.

When activated, the PPV sub program 1005 displays, on the terminalapparatus 500, a message that urges the user to purchase the program,and accepts an input from the user. More specifically, when informationwished to be displayed on the screen is sent to the CPU 514 of theterminal apparatus 500, a program running on the CPU 514 of the terminalapparatus 500 shows the message on the display 509 of the terminalapparatus 500. Then, when the user enters the personal identificationnumber via the input unit 513 of the terminal apparatus 500, the CPU 514of the terminal apparatus 500 accepts it, and sends it to the PPV subprogram 1005 running on the CPU 706 of the POD 504. The PPV sub program1005 sends, to the head end 101, the accepted personal identificationnumber via the network sub program 1003. When such personalidentification number is valid, the head end 101 notifies, via thenetwork sub program 1003, the PPV sub program 1005 of descramblinginformation required for descrambling such as a fourth key. The PPV subprogram 1005 provides the first descrambler unit 701 with the accepteddescrambling information such as the fourth key, and then the firstdescrambler unit 701 descrambles the input signal.

Referring to FIG. 5, each of the TS decoder A505 a and TS decoder B505 bperforms filtering on the signal accepted from the POD 504 via thedemultiplexer 515, and passes necessary data to the audio decoder A506a, the audio decoder B506 b, the video decoder A508 a, the video decoderB508 b, and the primary storage unit 510. FIG. 11A shows the TS decoderA505 a and FIG. 11B shows the TS decoder B505 b. PID filters 1101 a-1101f perform filtering on specified packet IDs. There are plural PIDfilters in the respective TS decoders. A section filter A1102 a and asection filter B1102 b perform filtering on data except for video andaudio, and store the resultant into the respective primary storagedevices. Here, a signal sent from the POD 504 is an MPEG2 transportstream. A detailed description about an MPEG2 transport stream is givenin the MPEG specification ISO/IEC138181-1, and therefore it is notexplained in detail in the present embodiment. An MPEG2 transport streamis composed of plural fixed length packets, and a packet ID is assignedto each packet.

FIG. 12 is a diagram showing the structure of a packet. 1200 is apacket, which contains fixed length 188 bytes. The top four bytes is aheader 1201 storing information for identifying the packet, and theother 184 bytes is a payload 1202 storing information wished to becarried. 1203 shows the breakdown of the header 1201. A packet ID isincluded in 13 bits from the 1^(st) to the 12^(th)-24^(th) bit. FIG. 13is a schematic diagram illustrating plural packet strings to betransmitted. A packet 1301 contains a packet ID “1” in its header andincludes the first information of video A in its payload. A packet 1302contains a packet ID “2” in its header and includes the firstinformation of audio A in its payload. A packet 1303 contains a packetID “3” in its header and includes the first information of audio B inits payload. A packet 1310 contains a packet ID “100” and includes thefirst information of data 1 in its payload.

A packet 1304 contains the packet ID “1” in its header and includes thesecond information of the video A in its payload, which is thesubsequent information of the packet 1301. Similarly, packets 1305,1311, 1326 and 1327 carry subsequent data of the other packets. Byconcatenating the contents of the payloads of packets with the samepacket IDs in the above manner, it is possible to reproduce video andaudio in successive order. Furthermore, while the contents of thepayloads of packets with the same packet IDs are concatenated, dataother than the video and audio is stored into the primary storage unit511.

Referring to FIG. 5, when the CPU 514 indicates, to the TS decoder A505a, the packet ID “1” as well as “the video decoder A508 a” as an outputdestination, the PID filter 1101 b of the TS decoder A505 a extractspackets with the packet ID “1” from the MPEG2 transport stream receivedfrom the POD 504 via the demultiplexer 515, and passes them to the videodecoder A508 a. In FIG. 5, therefore, only the video data is passed overto the video decoder A508 a. At the same time, when the CPU 514indicates, to the TS decoder A505 a, the packet ID “2” as well as “theaudio decoder A506 a”, the PID filter 1101 a of the TS decoder A505 aextracts packets with the packet ID “2” from the MPEG2 transport streamreceived from the POD 504, and passes them to the audio decoder A506 a.Furthermore, when the CPU 514 indicates, to the TS decoder A505 a, thepacket ID “100” as well as “the primary storage unit 511”, the PIDfilter 1101 c of the TS decoder A505 a extracts packets with the packetID “100” from the MPEG2 transport stream received from the POD 504, andpasses them to the primary storage device.

This processing of extracting only necessary packets according to packetIDs corresponds to filtering to be performed by the TS decoders 505. TheTS decoder A505 a is capable of performing more than one filteringprocessing concurrently at the instruction from the CPU 514.

Referring to FIG. 5, the audio decoder A506 a and the audio decoder B506b concatenate audio data embedded in the packets in the MPEG2 transportstream provided respectively by the TS decoder A505 a and the TS decoderB505 b, perform digital-to-analog conversion on the concatenated data,and output the resultant to the speaker 507.

The speaker 507 outputs the signals provided by the audio decoder A506 aand the audio decoder B506 b as audio.

The video decoder A508 a and the video decoder B508 b concatenate videodata embedded in the packets in the MPEG2 transport stream providedrespectively by the TS decoder A505 a and the TS decoder B505 b, performdigital-to-analog conversion on the concatenated data, output theresultant to the display device A520 a and the display device B520 b,and display the resultant on the display 509 in synthesized form. Thedisplay device A520 a and the display device B520 b are each configuredas shown in FIG. 15. In FIG. 15, a graphics device 1501 is used todisplay graphics. A video device 1502 is used to display video, and abackground device 1503 is used to display the background of video. Atthe final stage, video and graphics displayed on the respective devicesare outputted to the display 509 in synthesized form. As FIG. 16 shows,it is possible to integrate the display device A520 a and the displaydevice B520 b together. In FIG. 16, 1610 is the integration of thedisplay device A520 a and the display device B520 b. Assume, in FIG. 16,that the graphics device A1601, the video device A1603, and thebackground device A1505 are respectively the constituent elements of thedisplay device A520 a, and that graphics device B1602, the video deviceB1504, and the background device B1506 are respectively the constituentelements of the display device B520 b. Each of these devices areintegrated and outputted to the display 509.

A concrete constituent element of the display 509 is a CRT or a liquidcrystal and the like.

The secondary storage unit 510, concrete constituent elements of whichare a flash memory, a hard disk, and the like, stores and deletes dataand programs specified by the CPU 514. Stored data and programs arereferred to by the CPU 514. The stored data and programs are kept instorage even while the terminal apparatus 500 is powered off.

The primary storage unit 511, concrete constituent elements of which area RAM and the like, temporarily stores data and programs specified bythe CPU 514 and deletes them. Stored data and programs are referred toby the CPU 514. The stored data and programs are deleted when theterminal apparatus 500 gets powered off.

The ROM 512 is a read-only memory device, concrete constituent elementsof which are a ROM, a CD-ROM, and a DVD, and the like. The ROM 512stores a program to be executed by the CPU 514.

The input unit 513, concrete constituent elements of which are a frontpanel or a remote controller, accepts an input from the user. FIG. 14shows an example of the input unit 513 in the case where it isconfigured in the form of a front panel. 1400 is a front panel, whichcorresponds to the front panel unit 603 shown in FIG. 6. Such frontpanel 1400 is made up of seven buttons: an up-cursor button 1401, adown-cursor button 1402, a left-cursor button 1403, a right-cursorbutton 1404, an OK button 1405, a cancel button 1406, an EPG button1407, a two-window button 1408, and a window selection button 1409. Whenthe user presses down a button, the identifier of such pressed button isnotified to the CPU 514.

The CPU 514 executes the program stored in the ROM 512. According toinstructions from such program to be executed, the CPU 514 controls thetuner A501 a, the tuner B501 b, the QPSK demodulation unit 502, the QPSKmodulation unit 503, the POD 504, the TS decoder A505 a, the TS decoderB505 b, the display 509, the secondary storage unit 510, the primarystorage unit 511, the audio decoder A506 a, the audio decoder B506 b,the video decoder A508 a, the video decoder B508 b, the ROM 512, thedisplay device A520 a, and the display device B520 b.

FIG. 17 is a diagram showing an example structure of the program that isstored in the ROM 512 and executed by the CPU 514.

A program 1700 is made up of plural sub programs. To be more specific,the program 1700 is made up of an OS 1701, a service reproduction unit1702, a JavaVM 1703, a service manager 1704, and a Java library 1705.

The OS 1701 is a sub program to be activated by the CPU 514 when theterminal apparatus 500 is powered on. The OS 1701 is an abbreviation ofoperating system, an example of which is Linux™ and the like. The OS1701 is a generic name for a publicly known art made up of a kernel 1701a for executing a sub program in parallel with another sub program andof a library 1702 b, and therefore a detailed explanation is omitted. Inthe present embodiment, the kernel 1701 a of the OS 1701 executes theJavaVM 1703 as a sub program. Meanwhile, the library 1701 b providesthese sub programs with plural functions required for controlling theconstituent elements of the terminal apparatus 500.

Here, tuning is introduced as an example of such functions. With thefunction of tuning, tuning information including a frequency is receivedfrom another sub program and then passed over to the tuner A501 a or thetuner B501 b.

Here, consider the case where tuning information is passed over to thetuner A501 a. It is possible for the tuner A501 a to performdemodulation based on the provided tuning information, and pass thedemodulated data to the POD 504 via the multiplexer 516. As a result,the other sub programs can control the tuner A501 a via the library 1701b.

The service reproduction unit 1702 gives an instruction about thereproduction of a service, using a service identifier. The servicereproduction unit 1702, which is a Java program, accepts an input fromthe user via the JavaVM 1703. A description of service is given later.The relationship between a service and an identifier is pre-stored inthe secondary storage unit 510 as service information. FIG. 18 shows anexample of service information stored in the secondary storage unit 510.Service information is stored in tabular form. A column 1801 describesthe identifiers of services. A column 1802 describes service names. Acolumn 1803 describes tuning information. Here, tuning information,which is a value to be provided to the tuner A501 a, includes frequency,transmission rate, coding ratio, and the like. A column 1804 describesprogram numbers. Program numbers are numbers used to identify PMTsdefined by the MPEG2 standard. A description about PMT is given later.Each of lines 1811-1814 indicates a set of the identifier, service name,and tuning information of each service. The line 1811 describes a setthat includes “1” as an identifier, “Channel 1” as a channel name, afrequency of “312 MHz” as tuning information, and “101” as a programnumber. The service reproduction unit 1702 passes the identifier of aservice directly to the service manager 1704 in order to reproduce theservice. Processing to be performed between the service reproductionunit 1702 and the service manager 1704 is described in detail later.

Also, in FIG. 18, 1820 shows the identifier of the lastly selectedservice. When the user presses down the up-cursor 1401 and thedown-cursor 1402 on the front panel 1400 while the reproduction istaking place, the service reproduction unit 1702 receives a notificationabout such press from the input unit 513 via the CPU 514, and switchesthe service being reproduced to another one. First, the servicereproduction unit 1702 stores, in the secondary storage unit 510, theidentifier of the service that is currently reproduced. FIG. 19A, FIG.19B, and FIG. 19C show example identifiers of services stored in thesecondary storage unit 510. FIG. 19A shows that an identifier “3” isstored, and it is shown, by referring to FIG. 18, that a service withthe service name “TV 3” is being reproduced. When the user presses downthe up-cursor 1401 in a state illustrated in FIG. 19A, the servicereproduction unit 1702 refers to the service information shown in FIG.18, and passes the identifier “2” of a service with the service name of“Channel 2” to the service manager in order to newly reproduce a servicewith the service name of “Channel 2”, which is the previous service inthe table. At the same time, the service reproduction unit 1702 rewritesthe identifier into the service identifier “2” stored in the secondarystorage unit 510. FIG. 19B shows such rewritten service identifier.Meanwhile, when the user presses down the down-cursor 1402 in the stateillustrated in FIG. 19A, the service reproduction unit 1702 refers tothe service information shown in FIG. 18, and passes the identifier “4”of a service with the service name of “TV Japan” to the service managerin order to newly reproduce a service with the service name of “TVJapan”, which is the next service in the table. At the same time, theservice reproduction unit 1702 rewrites the identifier into the serviceidentifier “4” stored in the primary storage unit 511. FIG. 19C showssuch rewritten service identifier.

The JavaVM 1703 is a Java virtual machine that sequentially analyzes andexecutes programs written in the Java™ language. Programs written in theJava language are compiled into intermediate codes known as byte codeswhich do not depend on hardware. The Java virtual machine is aninterpreter that executes such byte codes. Some of the Java virtualmachines translate byte codes into an executable form which can beinterpreted by the CPU 514 and pass the resultant to the CPU 514, whichexecutes it. The JavaVM 1703 gets activated, with a Java program to beexecuted being specified by the kernel 1701 a. In the presentembodiment, the kernel 1701 a specifies the service manager 1704 as aJava program to be executed. A detailed commentary on the Java languageis given in many books that include “Java Language Specification (ISBN0-201-63451-1)”. Therefore, a detailed description about it is omittedhere. Also, a detailed commentary on the operation of the Java VM itselfis given in many books that include “Java Virtual Machine Specification(ISBN 0-201-63451-X)”. Therefore, a detailed description about it isomitted here.

The service manager 1704, which is a Java program written in the Javalanguage, is executed by the JavaVM 1703 sequentially. It is possiblefor the service manager 1704 to call and to be called by another subprogram not written in the Java language through the JNI (Java NativeInterface). A commentary on the JNI is given in many books that include“Java Native Interface”. Therefore, a detailed description about it isomitted here.

FIG. 20 shows the configuration of the service manager 1704. The servicemanager 1704 is comprised of a ServiceContext management unit 2001, aServiceContext obtainment unit 2002, a XAIT information obtainment unit2003, and a XAIT information storage unit 2004. The ServiceContextmanagement unit 2001 holds the identifier of a ServiceContext and theServiceContext in a pair. As FIG. 21 shows, a column 2101 describes theidentifiers of ServiceContexts, and a column 2102 describes theServiceContexts. A line 2103 indicates that the ServiceContextidentifier “1” is associated with a ServiceContext A for In-bandservice. A line 2104 indicates that a ServiceContext B for In-bandservice is identified by the ServiceContext identifier “2”. A line 2105indicates that a ServiceContext for Abstract service is identified bythe ServiceContext identifier “3”.

In-band service here is a unit of displaying/executing video, audio,Java programs and the like, and is a service defined in the ninthchapter in the DVB-MHP specification (formally known as ETSI TS 101 812DVB-MHP specification V1.0.2).

ServiceContexts are defined in the Java TV (Java TV API Version 1.0specification) specification. The ServiceContext for In-band serviceA2106 and the ServiceContext for In-band service B2107 specify a set ofresources required to execute one service and execute an In-band serviceusing such set of resources.

FIG. 22 shows either the ServiceContext for In-band service A2106 or theServiceContext for In-band service B2107. 2201 is a service executionunit, 2202 is a resource set holding unit, and 2203 is a resource setobtainment unit. When a service identifier is passed to the serviceexecution unit 2201, the service execution unit 2201 executes an In-bandservice by use of a set of resources indicated by the resource setholding unit 2202. The resource set holding unit 2202 is illustrated inFIG. 23. FIG. 23 shows an example in which a resource set identifier2301 and a set of resources 2302 (information that includes resource setinformation indicating one or more resources) are stored in a pair. Theresource set obtainment unit 2203 obtains the set of resources held bythe resource set holding unit 2202. In the present embodiment, theresource set obtainment unit 2203 is used only from the Java library1705.

FIG. 24 shows an example of resources. Resources shown in FIG. 24 arethe tuner A501 a, the tuner B501 b, the TS decoder A505 a, the TSdecoder B505 b, the audio decoder A506 a, the audio decoder B506 b, thevideo decoder A508 a, and the video decoder B508 b. 2410 and 2411indicate the respective sets of resources. The tuner A501 a, the tunerB501 b, the TS decoder A505 a, the TS decoder B505 b, the audio decoderA506 a, the audio decoder B506 b, the video decoder A508 a, and thevideo decoder B508 b are explained in FIG. 5, and therefore nodescription is given here.

Note that in the present embodiment, the tuner A501 a, the tuner B501 b,the TS decoder A505 a, the TS decoder B505 b, the audio decoder A506 a,the audio decoder B506 b, the video decoder A508 a, and the videodecoder B508 b are assumed to be resources, but it is possible to carryout the present embedment if another configuration is employed or ifother resources are included.

In order to operate one In-band service, the service identifier that iswished to be executed is indicated to the service execution unit 2201 ofthe ServiceContext A2002 or the ServiceContext B2003 managed by theservice manager 1704. FIG. 25 is a flowchart showing a series of itsprocessing. When the service reproduction unit 1702 wishes to execute anIn-band service, the service reproduction unit 1702 first requests theServiceContext obtainment unit 2002 of the service manager 1704 toobtain ServiceContexts (Step S2501). In response to this obtainmentrequest, the ServiceContext obtainment unit 2002 obtains theServiceContext A2106 or the ServiceContext B2107 from the ServiceContextmanagement unit 2001, and notifies the service reproduction unit 1702 ofthis (Step S2502). The service reproduction unit 1702 passes the serviceidentifier to the service execution unit 2201 of either of the obtainedservice ServiceContexts, that is, the ServiceContext A2106 or theServiceContext B2107 (Step S2503). The service execution unit 2201 ofthe ServiceContext A2106 or the ServiceContext B2107 that receives theservice identifier executes the service A2601 or the service B2602 forIn-band corresponding to such service identifier, using the set ofresources A2410 or the set of resources B2411 (Step S2504).

FIG. 26 shows the respective relationship among services, theServiceContexts and the sets of resources. The ServiceContext A2106executes the service for In-band A2601, using the set of resourcesA2410. The ServiceContext B2107 executes the service for In-band B2602,using the set of resources B2411. The other constituent elements are asshown in FIG. 24, and therefore no description is given here.

In the present embodiment, consider the case where the user turns thepower on, after which two-window display is selected by the press of thetwo-window button 408 on the front panel 1400.

When the user turns the power on, an In-band service indicated by thelastly selected service identifier stored in the secondary storage unit510 is executed.

The service reproduction unit 1702 passes the service identifier to theservice execution unit 2201 of the ServiceContext for In-band serviceA2106.

The service execution unit 2201 of the ServiceContext for In-bandservice A2106 first passes the service identifier to the Tuner 1705 cthat exists in the Java library 1705 so as to request for tuning. Inorder to make a request for tuning, the service execution unit 2201operates in a manner as shown in the flowchart in FIG. 27. The serviceexecution unit 2201 requests the Tuner 1705 c to obtain an instance of aJava class representing the tuner A501 a (Step S2701). The Tuner 1705 cidentifies the invoker of the instance of the Java class representingthe tuner A501 a (Step S2702). For example, the Tuner 1705 c determines,by a thread, the invoker that has requested the instance. Here, it ispossible for a thread to identify a Java program according to a group towhich such thread belongs to. And it is possible to obtain a servicefrom such Java program, and then identify the ServiceContext A2106 aftermaking an enquiry to the service manager. The Tuner 1705 c obtains theset of resources A2410 from the resource set obtainment unit 2203 of theServiceContext A2106 identified in Step S2702 (Step S2703). The Tuner1705 c returns an instance of a Java class that represents a tuner andthat uses the tuner A501 a included in the set of resources 2410obtained in Step S2703 (Step S2704). The service execution unit 2201indicates the instance obtained in Step S2704 to request the Tuner 1705c to perform tuning (Step S2705). Upon receipt of the tuning request,the Tuner 1705 c obtains tuning information with reference to theservice information stored in the secondary storage unit 510. When theservice execution unit 2201 of the ServiceContext for In-band serviceA2001 passes the service identifier “2” to the Tuner 1705 c, the Tuner1705 c refers to the line 1812 in FIG. 18 to obtain the correspondingtuning information “156 MHz”. The Tuner 1705 c passes the tuninginformation to the tuner A501 a via the library 1701 b of the OS 1701.The tuner A501 a demodulates the signal sent from the head end 101according to the provided tuning information, and passes the demodulatedsignal to the POD 504 via the multiplexer 516.

Next, the service execution unit 2201 of the ServiceContext for In-bandservice A2001 requests the CA 1705 d in the Java library 1705 to performdescrambling. The CA 1705 d provides information required fordescrambling to the POD 504 via the library 1701 b of the OS 1701. ThePOD 504 descrambles the signal provided from the tuner A501 a based onthe provided information, and passes the descrambled signal to the TSdecoder 505 via the demultiplexer 515.

Next, the service execution unit 2201 of the ServiceContext for In-bandservice A2001 provides a JMF 1705 a inside the Java library 1705 withthe service identifier, so as to request for the reproduction of videoand audio.

FIG. 28 is a flowchart.

First, the service execution unit 2201 requests the JMF 1705 a to obtainan instance of a Java class representing resources (the TS decoder A505a, the audio decoder 506 a and the video decoder 508 a) that arerequired for reproducing video and audio (Step S2801).

Using a thread, for example, the JMF 1705 a identifies the invoker ofthe instance of the Java classes representing the resources required forreproducing video and audio (Step S2802). Here, it is possible for athread to identify a Java program according to a group to which suchthread belongs to. And it is possible to obtain a service from such Javaprogram, and then identify the ServiceContext A2106 after making anenquiry to the service manager.

The JMF 1705 a obtains the set of resources A2410 from the resource setobtainment unit 2203 of the ServiceContext A2106 specified in Step S2802(Step S2803).

The JMF 1705 a returns the instance of the Java class that represents aset of resources required for reproducing video and audio included inthe set of resources 2410 obtained in Step S2803 (Step S2804).

The service execution unit 2201 requests the JMF 1705 a to reproducevideo and audio, using the instance obtained in Step S2804 (Step S2805).Upon receipt of the reproduction request, the JMF 1705 a obtains, from aPAT and a PMT, packet IDs used to identify the video and audio to bereproduced. PAT and PMT are tables defined by the MPEG-2 standard thatshow the program line-up included in an MPEG2 transport stream. PAT andPMT are carried in the payloads in packets included in an MPEG2transport stream, together with audio and video. Refer to thespecification for a detailed description of PAT and PMT. Here, only anoverview of PAT and PMT is given.

PAT, which is an abbreviation of Program Association Table, is carriedin packets with the packet ID “0”. In order to obtain the PAT, the JMF1705 a indicates, to the TS decoder A505 a, the packet ID “0” and theCPU 514 through the library 1701 b of the OS 1701. Then, the TS decoderA505 a performs filtering based on the packet ID “0”, and passes theresultant to the CPU 514. Accordingly, the JMF 1705 a can collect thePAT packets.

FIG. 29 illustrates a table that schematically shows an example of thecollected PAT information. A column 2901 describes program numbers. Acolumn 2902 describes packet IDs. The packet IDs shown in the column2902 are used to obtain the PAT. Each of lines 2911-2913 is a pair ofthe program number of a service and a packet ID corresponding to it.Here, three services are defined. The line 2911 defines a pair of theprogram number “101” and the packet ID “501”.

Assuming that the service identifier provided to the JMF 1705 a is “2”,the JMF 1705 a refers to the line 1812 in FIG. 18, so as to obtain theprogram number “102” corresponding to such service identifier, and thenrefers to the line 2912 in the PAT shown in FIG. 29, so as to obtain thepacket ID “502” corresponding to the program number “102”. PMT, which isan abbreviation of Program Map Table, is carried in packets with thepacket IDs specified in the PAT. In order to obtain the PMT, the JMF1705 a indicates, to the TS decoder A505 a, a packet ID and the CPU 514through the library 1701 b of the OS 1701. Here, a packet ID to bespecified is “502”. Then, the TS decoder A505 a performs filtering basedon the packet ID “502”, and passes the resultant to the CPU 514.Accordingly, the JMF 1705 a can collect the PMT packets.

FIG. 30 illustrates a table that schematically shows an example of thecollected PMT information. A column 3001 describes stream types. Acolumn 3002 describes packet IDs. Information specified in therespective stream types is carried in the payloads of packets with thepacket IDs specified in the column 3002. A column 3003 describesadditional information. Each of lines 3011-3014 is a pair of a packet IDand the type of information being transmitted, which is known as anelementary stream. The line 3011, which is a pair of the stream type“audio” and the packet ID “5011”, indicates that audio data is stored inthe payload of the packet with the packet ID “5011”. The JMF 1705 aobtains, from the PMT, the packet IDs of the video and audio to bereproduced. Referring to FIG. 30, the JMF 1705 a obtains the audiopacket ID “5011” from the line 3011, and the video packet ID “5012” fromthe line 3012.

Then, the JMF 1705 a provides the TS decoder A505 a with pairs of theobtained audio packet ID and the audio decoder A506 a as an outputdestination as well as the video packet ID and the video decoder A508 aas an output destination, via the library 1701 b of the OS 1701. The TSdecoder A505 a performs filtering based on such provided packet IDs andthe output destinations. Here, the packet with the packet ID “5011” ispassed to the audio decoder A506 a and the packet with the packet ID“5012” is passed to the video decoder A508 a. The audio decoder A506 aperforms digital-to-analog conversion on the provided packets, so as toreproduce the audio via the speaker 507. The video decoder A508 aperforms digital-to-analog conversion on the provided packets, so as tooutput the resultant to the display device A520 a, and displays theresultant on the display 509 in synthesized form.

Finally, the service execution unit 2201 of the ServiceContext forIn-band service A2106 provides the service identifier to an AM 1705 b inthe Java library 1705, so as to request for data broadcast reproduction.Here, data broadcast reproduction means to extract a Java programincluded in the MPEG2 transport stream and cause the JavaVM 1703 toexecute it. As a technique for embedding a Java program into an MPEG2transport stream, a method known as DSMCC is used, which is described inthe MPEG specification ISO/IEC138181-6. A detailed explanation of DSMCCis omitted here. DSMCC specification defines a method of encoding a filesystem comprised of directories and files used by a computer, in packetswithin an MPEG2 transport stream. Information about the Java program tobe executed is carried in packets in the MPEG2 transport stream in theform of AIT. AIT is an abbreviation of Application Information Tablewhose definition is given in the tenth chapter of the DVB-MHP standard(formally known as ETSI TS 101 812 DVB-MHP specification V1.0.2).

The AM 1705 b determines, by a thread, an invoker Java program of the TSdecoder A505 a to be used, and identifies it by obtaining theServiceContext A2106. First, in order to obtain the AIT, the AM 1705 bobtains the PAT and PMT as in the case of the JMF 1705 a, and obtainsthe packet ID of the packet that stores the AIT. Assuming that “2” isthe provided service identifier and that the PAT shown in FIG. 29 andthe PMT shown in FIG. 30 are being transmitted, the AM 1705 b obtainsthe PMT shown in FIG. 30 according to the same procedure followed by theJMF 1705 a. Subsequently, the AM 1705 b extracts, from the PMT, thepacket ID of the elementary stream whose stream type is “Data” and whichhas “AIT” as additional information. As shown in FIG. 30, the elementarystream in the line 3013 corresponds to such elementary stream, andtherefore the AM 1705 b obtains the packet ID “5013” from it.

The AM 1705 b provides the TS decoder A505 a with the packet ID of theAIT and the primary storage unit 511 as an output destination throughthe library 1701 b of the OS 1701. Then, the TS decoder A505 a performsfiltering based on such provided packet ID, and stores the AIT into theprimary storage unit 511. Accordingly, the AM 1705 b can collect the AITpackets. FIG. 31 is a table that schematically shows an example of thecollected AIT information. A column 3101 describes identifiers of Javaprograms. A column 3102 describes control information for controllingthe Java programs. The control information includes “autostart”,“present”, and “kill”. “autostart” means that the terminal apparatus 500automatically executes the program promptly. “present” means that theprogram is not executed automatically. “kill” means that the program isto be terminated. A column 3103 describes DSMCC identifiers used toextract packet IDs that include Java programs in the DSMCC format. Acolumn 3104 describes program names of the Java programs. Each of lines3111 and 3112 is a set of information about a Java program. The Javaprogram defined in the line 3111 is a set of an identifier “301”,control information “autostart”, a DSMCC identifier “1”, and a programname “a/TopXlet”. The Java program defined in the line 3112 is a set ofan identifier “302”, control information “present”, a DSMCC identifier“1”, and a program name “b/GameXlet”. Here, these two Java programs havethe same DSMCC identifier. This indicates that two Java programs areincluded in the file system which has been encoded according to the sameDSMCC method. Here, only four pieces of information are specified forthe respective Java programs, but more pieces of information arespecified in actuality. Refer to the DVB-MHP specification for detail.

The AM 1705 b finds the “autostart” Java program from the AIT, andextracts the corresponding DSMCC identifier and Java program name.Referring to FIG. 31, the AM 1705 b extracts the Java program in theline 3111, and obtains the DSMCC identifier “1” and the Java programname “a/TopXlet”.

Next, the AM 1705 b obtains, from the PMT, the packet ID of packets thatstore Java programs in the DSMCC format, using the DSMCC identifierobtained from the AIT. More specifically, the AM 1705 b obtains, fromthe PMT, the packet ID included in the elementary stream whose streamtype is “Data” and whose DSMCC identifier in the additional informationmatches.

Here, assuming that such DSMCC identifier is “1” and the PMT is the oneshown in FIG. 30, the elementary stream in the line 3014 satisfies theabove condition. Therefore, the packet ID “5018” is to be extracted.

The AM 1705 b indicates, to the TS decoder A505 a, the packet ID ofpackets in which data is embedded in the DSMCC format as well as theprimary storage unit 511 as an output destination through the library1701 b of the OS 1701. Here, the packet ID “5014” is provided. Then, theTS decoder A505 a performs filtering based on the provided packet ID,and stores the DSMCC-format data into the primary storage unit 511.Accordingly, the AM 1705 b can collect the required packets. The AM 1705b reconstructs the file system from the collected packets according tothe DSMCC method, and stores the reconstructed file system into theprimary storage unit 511. The process for extracting data such as thefile system from packets in the MPEG2 transport and storing theextracted data into storage units such as the primary storage unit 511is hereinafter called download.

FIG. 32 shows an example of the downloaded file system. In the diagram,circles represent directories and squares represent files, where 3201 isa root directory, 3202 is a directory “a”, 3203 is a directory “b”, 3204is a file “TopXlet. class”, and 3205 is a file “GameXlet. class”.

Subsequently, the AM 1705 b passes, to the JavaVM 1703, a Java programto be executed out of the file system downloaded into the primarystorage unit 511. Here, assuming that the Java program name to beexecuted is “a/TopXlet”, a file “a/TopXlet. class” resulted fromappending “. class” to the above Java program name is a file to beexecuted. “/” is a delimiter between a directory and a file name, and asshown in FIG. 32, the file 3204 is a Java program to be executed. Next,the AM 1705 b passes the file 3204 to the JavaVM 1703.

The JavaVM 1703 executes such received Java program. FIG. 33 shows anexample of how an In-band service indicated by the service identifier“2” is executed. 509 is the display, and 603 and 606 are as shown inFIG. 6. 3301 is an In-band service identified by the service identifier“2”, and 3302 is an icon that is displayed by the executed Java program.For example, in response to the user's pressing down of the “OK” button1405 on the front panel, it is also possible to give a full-screendisplay of a total information program 3401, as shown in FIG. 34.

Next, when the user presses down the “two-window” button 1408 on thefront panel 1400, two services are displayed. For example, the servicereproduction unit 1702 passes the service identifier “1” to the serviceexecution unit 2201 of the ServiceContext for In-band service B2107.

In this case, the service B2602 is executed in the same manner by use ofthe tuner B501 b, the TS decoder B505 b, the audio decoder B506 b, andthe video decoder B508 b shown in FIG. 5. FIG. 35 shows an example casewhere two services are displayed. In FIG. 35, 3501 is an In-band servicethat is indicated by the service identifier “1”. Descriptions of theother constituent elements are omitted here, since they are shown inFIG. 33. 3502 is a cursor. In the case where the input unit takes theform of the front panel 1400, the cursor 3502 moves, as shown in FIG.36, by the press of the “window selection” button 1409. Furthermore, thecursor 3502 automatically disappears after a certain period of time.

In FIG. 36, the cursor 3502 is placed on the In-band service indicatedby the service identifier “2”. In this case, when the user presses thedown cursor button 1402, for example, the service execution unit 2201 ofthe ServiceContext A2202 that is executing the In-band service indicatedby the service identifier “2” receives another service identifier, e.g.the service identifier “3”, terminates the reproduction of the video andaudio as well as the execution of the Java program which are included inthe In-band service A2601 and which are being carried out by theServiceContext A2002 through each library included in the Java library1705, through each library included in the same Java library 1705, andthen performs the reproduction of the video and audio as well as theexecution of a Java program that are included in a new In-band service,based on the newly received service identifier “3”. When this is done,the In-band service B2602 that is executed on the ServiceContext B2403keeps on running, without being terminated. FIG. 37 shows an examplecase where the service identifier “3” and the service identifier “1” aredisplayed concurrently. 3701 is an In-band service that is indicated bythe service identifier “3”. The Java library 1705 is a collection ofplural Java libraries stored in the ROM 512. In the present embodiment,the Java library 1705 includes the JMF 1705 a, the AM 1705 b, the Tuner1705 c, the CA 1705 d, a POD lib 1705 e, and the like.

In the present embodiment, it is also possible to omit the ROM 512 bystoring information stored in the ROM 512 in the secondary storage unit510. Furthermore, it is also possible that the secondary storage unit510 is made up of plural sub secondary storage units, and each subsecondary storage unit stores different information, so that informationcan be stored in segments. For example, one sub secondary storage unitmay store only tuning information, another sub secondary storage unitmay store the library 1201 b of the OS 1201, and another different subsecondary storage unit may store a downloaded Java program.

An Abstract service is made up of one or more Java programs. Abstractservice, which is independent of tuning, is implemented as an EPG, forexample. EPG is an abbreviation of Electric Program Guide. A descriptionof EPG is given later.

A ServiceContext for Abstract service executes Abstract services.

FIG. 39 shows a ServiceContext for Abstract service. A ServiceContextfor Abstract service 2108 is comprised of a service execution unit 3901,a ServiceContext setting unit 3902, and a ServiceContext holding unit3903. When the service execution unit 3901 executes a service, theServiceContext setting unit 3902 identifies a set of resources to beused, by associating the ServiceContext for Abstract service with aServiceContext for In-band service and then by having the ServiceContextholding unit 3903 to hold the associated ServiceContexts.

The XAIT information obtainment unit 2003 of the service manager 1704carries out a bilateral communication with the head end 101 through thePOD lib 1705 e included in the Java library 1705. This bilateralcommunication can be realized by the POD Lib 1705 e through the use ofthe library 1701 b of the OS 1701, as well as through the use of theQPSK demodulation unit 502 and the QPSK modulation unit 503 via the POD504.

Through the above communication, the XAIT information obtainment unit2003 of the service manager 1704 receives, from the head end 101,information about Java programs which the terminal apparatus 500 shouldstore in the secondary storage unit 510. Such information is called XAITinformation. The XAIT information is transmitted between the head end101 and the POD 504 in an arbitrary form. The present invention can becarried out regardless of transmission format, as long as informationrequired as XAIT is included.

FIG. 41 illustrates a table that schematically shows an example of theXAIT information obtained from the head end 101. A column 4101 describesthe identifiers of Abstract services. These identifiers of Abstractservices each correspond to one Abstract service. A column 4102describes control information for controlling the Abstract services. Thecontrol information includes “true” and “false”. “true” means that theprogram is executed automatically when the terminal apparatus 500 ispowered on, and “false” means that the program is not to be executedautomatically. A column 4103 describes DSMCC identifiers used to extractpacket IDs that include Java programs in the DSMCC format. A column 4104describes the program names of the Java programs. A column 4105describes the priorities of the Java programs. A column 4106 describescontrol information for controlling the Java programs, and a Javaprogram is executed if it indicates “autostart” when a service isexecuted. A column 4107 describes identifiers of the Java programs. Eachof lines 4111, 4112 and 4113 is a set of information about a Javaprogram. The Java program defined in the line 4111 is a set of anidentifier “701”, service control information “true”, a Java programidentifier “7011”, a DSMCC identifier “1”, a program name “a/EPGXlet”, aJava program priority “200”, and Java program control information“autostart”. Here, seven pieces of information are specified for therespective Java programs, but the present invention can be carried outeven when more or fewer pieces of information are defined.

When the XAIT information is received by the XAIT information obtainmentunit 2003, the service manager 1704 stores the file system from theMPEG2 transport stream into the primary storage unit 511 by use of theXAIT information storage unit 2004, according to the same procedure asthe one for downloading the Java program from the AIT information.Subsequently, the service manager 1704 copies such stored file system tothe secondary storage unit 510. Note that it is also possible todownload the file system not via the primary storage unit 511 butdirectly into the secondary storage unit 510.

Note that the copied file system is stored into the secondary storageunit 510 in the present embodiment, but it is also possible to store itinto the primary storage unit 511. It should be noted, however, that allstored information is lost at power-off time, in the case where the filesystem is stored into the primary storage unit 511.

Next, the XAIT information storage unit 2004 of the service manager 1704stores, in the secondary storage unit 510, the result of associating theXAIT information with a storage position of the downloaded file system.FIG. 42 shows an example of the XAIT information and the downloaded filesystem stored in the secondary storage unit 510 in association with eachother. Elements in FIG. 42 that have the same numbers as those in FIG.41 are the same as each other, and therefore an explanation for suchelements is omitted. A column 4411 stores the storage positions ofcorresponding downloaded file systems. In FIG. 42, such storagepositions are indicated by arrows. 4210 is a downloaded file system,where a top directory 4211, a directory “a” 4212, a directory “b” 4213,a file “EPGXlet. class” 4214, a file “TOPXlet. class” 4215, and a file“PVXlet. class” 4216 are included.

Here, the XAIT information is stored after the Java program is stored,but it is also possible for the XAIT information to be stored before theJava program. An Abstract service indicated by the identifier of anAbstract service whose control information is “true” is automaticallyexecuted by the terminal apparatus 500.

After the service manager 1704 is indicated to the JavaVM 1703 and theservice manager 1704 is activated by the JavaVM 1703, the servicereproduction unit 1702 obtains, from the XAIT information storage unit2004, an Abstract service whose control information is “true” via theXAIT information obtainment unit 2003, with reference to the controlinformation of each Abstract service, obtains the ServiceContext forAbstract service 2108 from the ServiceContext obtainment unit 2002, andcauses the service execution unit 2201 of the ServiceContext forAbstract service 2108 to execute it.

In the present embodiment, consider the case where an EPG is executed asa Java program included in an Abstract service.

FIG. 81 shows an example configuration of an EPG. An EPG 8101 iscomprised of a program display unit 8102 for displaying a list ofprograms to the user as well as for accepting an input from the user,and a program reproduction unit 8103 for selecting services. When theuser turns the power on, the lastly executed service is shown on thedisplay 509, and a Java program indicating the EPG 8101 is not displayedon the screen although it is being executed. In the case where the inputunit 513 takes the form of the front panel shown in FIG. 14, such Javaprogram is shown for the first time on the display 509 by the user'spressing the EPG button 1407 on the input unit 513.

In the present embodiment, consider the case where the user presses downthe EPG button 1407 on the input unit 513 when the display 509 is asshown in FIG. 37. When the user presses down the EPG button 1407 on theinput unit 513, the program display unit 8102 of the EPG 8101 receivesits identifier, and shows program information on the display 509. FIG.38 illustrates the display 509 when the EPG button 1407 is pressed down.3801 is an EPG. FIG. 40A and FIG. 40B show examples of the EPG 3801displayed on the display 509. Referring to FIG. 40A, the programinformation is displayed on the display 509 in a grid pattern. A column4001 describes time information. A column 4002 describes a service name“Channel 1” and programs to be broadcast during time periodscorresponding to the respective times described in the column 4001. Itis shown that a program “News 9” is broadcast from 9:00 to 10:30, and“Cinema AAA” is broadcast from 10:30 to 12:00 on “Channel 1”. A column4003 describes a service name “Channel 2” and programs to be broadcastduring time periods corresponding to the respective times described inthe column 4001, as in the case of the column 4002. A program “CinemaBBB” is broadcast from 9:00 to 11:00, and “News 11” is broadcast from11:00 to 12:00. 4030 is a cursor. The cursor 4030 moves at the press ofthe left-cursor 1403 or the right-cursor 1404 on the front panel 1400.When the right-cursor 1404 is pressed down in the state illustrated inFIG. 40A, the cursor 4030 moves toward right as shown in FIG. 40B.Meanwhile, when the left-cursor 1403 is pressed down in the stateillustrated in FIG. 40B, the cursor 4030 moves toward left as shown inFIG. 40A.

When the OK button 1405 on the front panel 1400 is pressed down in thestate shown in FIG. 40A, the program display unit 8102 notifies thereproduction unit 8103 of the identifier of “Channel 1”. Meanwhile, whenthe OK button 1405 on the front panel 1400 is pressed down in the stateshown in FIG. 40B, the program display unit 1702 a notifies thereproduction unit 1402 b of the identifier of “Channel 2”.

Furthermore, the program display unit 8102 periodically stores programinformation to be displayed from the head end 101 into the primarystorage unit 511 via the POD 504. Generally, it takes time to obtainprogram information from the head end. However, it becomes possible toquickly display a program table by displaying the program informationthat is pre-stored in the primary storage unit 511 at the press of theEPG button 1407 on the input unit 513.

4010 and 4011 in FIG. 40A and FIG. 40B show the video and audio beingreproduced of the respective services on which the cursors are placed.When reproducing video and audio, a Java program included in an Abstractservice specifies the identifiers of video and audio that are wished tobe reproduced, using the program JMF 1705 a, and reproduces them usingthe audio decoder A506 a or the audio decoder B506 b, and the videodecoder A508 a or the video decoder B508 b.

In the present embodiment, in order to specify which set of resources isto be used for reproducing video and audio by a Java program included inan Abstract service running on the ServiceContext for Abstract service,the ServiceContext for Abstract service is associated with either of theServiceContexts for In-band service A2106 or B2107.

FIG. 39 shows the ServiceContext for Abstract service. TheServiceContext setting unit 3902 associates the ServiceContext forAbstract service with the ServiceContext for In-band service A. By aJava program indicating the ServiceContext for In-band A2106 to theServiceContext setting unit 3902, it becomes possible to identify theset of resources A2410 as a set of resources to be used.

FIG. 43 is a diagram showing the ServiceContext for Abstract servicebeing associated with the ServiceContext for In-band service A. 2108 isthe ServiceContext for Abstract service, on which an Abstract serviceE4301 runs. The other elements are the same as those shown in FIG. 26,and therefore no description is given of them. In FIG. 43, it ispossible to specify a set of resources identified by the ServiceContextA2106 by associating the ServiceContext 2108 for Abstract service withthe ServiceContext A2106.

FIG. 44 shows an example method of associating the ServiceContext forAbstract service with a ServiceContext for In-band service.

In FIG. 44, the ServiceContext for Abstract service is defined asAbstractServiceContext class 4402. The AbstractServiceContext class 4402inherits ServiceContext class 4401 of the ServiceContext for In-bandservice. The service execution unit 2201 shown in FIG. 39 is the same asthe ServiceContext class 4401. The ServiceContext setting unit 3902defines a method. In FIG. 44, a setServiceContext (ServiceContext)method 4410 is defined as an example. It is possible to identify a setof resources held by the ServiceContext for In-band service byspecifying, as an argument of such method, the ServiceContext forIn-band service which is wished to be associated.

In the present embodiment, it is possible for the ServiceContext forAbstract service to identify a set of resources by specifying, as anargument of setServiceContext (ServiceContext), one of twoServiceContexts for In-band service. For example, it is possible tospecify which one of the two In-band services 3701 and 3501 shown inFIG. 37 should display an Abstract service.

FIG. 45 is a flowchart showing processing to be performed by a Javaprogram included in an Abstract service when reproducing video andaudio.

The present embodiment presents an example in which a Java programrepresenting an EPG uses resources for the ServiceContext for In-bandservice A as shown in FIG. 38. The Java program obtains a ServiceContextfor In-band service from the ServiceContext obtainment unit of theservice manager 1704 (Step S4501). Next, using setServiceContext(ServiceContext) 4410, the Java program associates the ServiceContextfor Abstract service 2108 with the ServiceContext for In-band serviceA2106. The ServiceContext specified as an argument is to be retained bythe ServiceContext holding unit 3903 of the ServiceContext for Abstractservice 2108 (Step S4502). The Java program requests the JMF 1705 a toobtain an instance (resource set information) of a Java classrepresenting a set of resources, and to reproduce video and audio usingsuch instance (Step S4503). The JMF 1705 a reproduces the specifiedvideo and audio using the set of resources A2410 specified by suchinstance (Step S4504). Here, the details of Step S4503 are as shown inFIG. 28.

Furthermore, when a Java program included in the ServiceContext forAbstract service wishes to reproduce two pieces of video and audio data,it is possible to reproduce such pieces video and audio data byfollowing the procedure shown in FIG. 46.

First, the Java program obtains ServiceContexts for In-band service fromthe ServiceContext obtainment unit of the service manager 1704 (StepS4601). Next, using setServiceContext (ServiceContext) 4410, the Javaprogram associates the ServiceContext for Abstract service 2108 with theServiceContext for In-band service A2106 (Step S4602). The Java programrequests the JMF 1705 a to obtain an instance of a Java classrepresenting a set of resources, and to reproduce video and audio byspecifying such video and audio using such instance (Step S4603). TheJMF 1705 a reproduces the specified video and audio using the set ofresources A2410 specified by such instance (Step S4604). Then, the Javaprogram associates the ServiceContext for Abstract service with theServiceContext for In-band service B2107 by use of a method ofAbstractServiceContext, setSeriveContext(ServiceContextB) 4410 (StepS4605). The Java program requests the JMF 1705 a to obtain an instanceof a Java class representing a set of resources, and to reproduce videoand audio by specifying such video and audio using such instance(S4606). The JMF 1705 a reproduces the specified video and audio usingthe set of resources A2410 specified by such instance (Step S4607). Asdescribed above, it is also possible to control plural sets ofresources. Note that in the present embodiment, a ServiceContext forIn-band service is explicitly associated to the ServiceContext forAbstract service, but it is also possible to associate a certainServiceContext for In-band service by default.

Also, the present embodiment presents an example of the ServiceContextfor Abstract service that is associated with a ServiceContext forIn-band service, but there may exist a ServiceContext for Abstractservice that cannot be associated with another ServiceContext.

Note that the POD 504 is detachable in the present embodiment, but it isalso possible to carry out the present invention if the POD 504 isembedded into the terminal apparatus 500. When the POD 504 is embedded,the CPU 706 of the POD 504 may be removed and the CPU 514 performs theoperation of the CPU 706.

Moreover, it is also possible to carry out the present invention if notonly downloaded Java programs but also pre-stored Java programs are tobe registered in the POD Lib 1705 e. Furthermore, it is also possible toprovide a slot unit for inserting/ejecting a detachable storage mediumsuch as an SD memory card, so as to load Java programs from it. Also, anetwork unit to get connected to a network may be provided, so as toload Java programs from the Internet.

Second Embodiment

The present embodiment describes a ServiceContext for Abstract servicewith a configuration that is different from that of the ServiceContextfor Abstract service shown in FIG. 39 that is defined in the firstembodiment. The other part is the same as the first embodiment, andtherefore descriptions are given in the present embodiment, focusing onthe configuration of the ServiceContext for Abstract service, especiallyhow the ServiceContext for Abstract service and a ServiceContext forIn-band service are associated with each other.

FIG. 47 shows the ServiceContext for Abstract service in the presentembodiment. Its constituent elements are a service execution unit 4701and the ServiceContext holding unit 3903. The service execution unit4701 associates the ServiceContext for Abstract service with aServiceContext for In-band service by receiving the ServiceContext forIn-band service at the time when the service execution unit 4701 of theServiceContext for Abstract service 2108 receives the serviceidentifier. Such received ServiceContext for In-band service is retainedin the ServiceContext holding unit 3903. FIG. 49 shows an example methodof associating the ServiceContext for Abstract service with theServiceContext for In-band service. The ServiceContext 4401 shown inFIG. 49 is as defined in FIG. 44. The AbstractServiceContext class 4902inherits the ServiceContext class 4401. The service execution unit 4701newly has select (Service, ServiceContext) 4911, which is a method forexecuting services. Using this method, an Abstract service specified asan argument is executed, and at the same time, a ServiceContext forIn-band service specified as an argument is stored into theServiceContext holding unit 3903 so as to be associated with the aboveAbstract service. Accordingly, when the Abstract service specified onthe ServiceContext for Abstract service is to be executed, a set ofresources specified by such ServiceContext for In-band service is used.Furthermore, when a Java program included in the Abstract servicerequires some resources (e.g. reproduction of video and audio),resources identified by the ServiceContext specified as an argument inthe select method are to be used.

FIG. 50 is a flowchart in the present embodiment. The servicereproduction unit 1702 obtains a ServiceContext for In-band service fromthe ServiceContext obtainment unit 2002 of the service to manager 1704(Step S5001). When executing an Abstract service, the servicereproduction unit 1702 stores a ServiceContext for In-band servicespecified as an argument into the ServiceContext holding unit 3903, byspecifying such ServiceContext for In-band service in theselect(Service, ServiceContext) method 4911 of the Abstract service(Step S5002). The Java program requests the JMF 1705 a to obtain aninstance of a Java class representing a set of resources, and toreproduce video and audio by specifying such video and audio using suchinstance (Step S5003). The JMF 1705 a reproduces the specified video andaudio using the set of resources A2410 or the set of resources 82411identified by the instance obtained in Step S5003 (Step S5004). Here,the details of Step S5003 are as shown in FIG. 28.

Third Embodiment

The present embodiment is different from the first embodiment in themethod of associating the ServiceContext for Abstract service 2108 witha ServiceContext for In-band service. The other part is the same as thefirst embodiment, and therefore descriptions are given in the presentembodiment, focusing on how the ServiceContext for Abstract service anda ServiceContext for In-band service are associated with each other.

FIG. 51 shows the configuration of the service manager 1704 in thepresent embodiment. In the present embodiment, the ServiceContext forAbstract service and a ServiceContext for In-band service are associatedby the ServiceContext mapping unit 5101 of the service manager 1704. TheServiceContext mapping unit 5101 holds the relationship between theServiceContext for Abstract service and a ServiceContext for In-bandservice. FIG. 52 shows the configuration of the ServiceContext mappingunit 5101. The ServiceContext mapping unit 5101 is comprised of aServiceContext mapping holding unit 5201, a ServiceContext for In-bandservice obtainment unit 5202, and a ServiceContext mapping achievementunit 5203. FIG. 53 shows an example of the ServiceContext mappingholding unit 5201. In FIG. 53, a column 5303 describes theServiceContext for Abstract service and a column 5304 describesServiceContexts for In-band service. In lines 5301 and 5302,ServiceContexts for In-band service and Abstract service in the sameline are associated with each other. Service contexts in the same lineuse the same set of resources.

Note that in FIG. 53, one ServiceContext for In-band service isassociated with one ServiceContext for Abstract service at greatest, butit is possible to carry out the present invention if a plurality ofServiceContexts for Abstract service are associated with a singleServiceContext for In-band service.

The ServiceContext for In-band service obtainment unit 5202 obtains,from the ServiceContext mapping holding unit 5203, a ServiceContext forIn-band service to which the ServiceContext for Abstract service isassociated, and returns it. The ServiceContext mapping achievement unit5203 associates the ServiceContext for Abstract service and theServiceContext for In-band service with each other. FIG. 48 shows theServiceContext for Abstract service according to the present embodiment.The ServiceContext for Abstract service includes a service executionunit 4801. Upon receipt of a service identifier, the service executionunit 4801 obtains a ServiceContext for In-band service stored in theServiceContext mapping unit 5101, and specifies a set of resources toexecute a service.

FIG. 54 shows an example method of associating the ServiceContext forAbstract service and a ServiceContext for In-band service. In FIG. 54,the ServiceContext mapping unit is represented as ServiceContextMapclass 5401. In order to implement the ServiceContext mapping achievementunit 5203, void setServiceContext (AbstractServiceContext,ServiceContext) 5413 is defined. getServiceContext(AbstractServiceContext) 5412 obtains a ServiceContext to which theAbstractServiceContext class specified as an argument is currentlyassociated, from serviceContextMap 5411 that represents theServiceContext mapping holding unit 5201.setServiceContext(AbstractServiceContext, ServiceContext) 5413associates two ServiceContexts specified as arguments, and stores theassociated ServiceContexts in the serviceContextMap. Meanwhile, as amethod for implementing the ServiceContext for In-band serviceobtainment unit 5202, ServiceContext getServiceContext(AbstractServiceContext)) 5412 for obtaining a ServiceContext forIn-band service from the serviceContextMap 5411 is defined.

FIG. 55 shows a flowchart in the present embodiment.

A Java program included in an Abstract service obtains a ServiceContextfor In-band service from the ServiceContext obtainment unit 2002 of theservice manager 1704 (Step S5501). Next, usingsetServiceContext(AbstractService, ServiceContext) 5413, the Javaprogram associates the ServiceContext for Abstract service 2108 with theServiceContext A0106 for In-band service (Step S5502). Then, the Javaprogram requests the JMF 1705 a to obtain an instance of a Java classrepresenting a set of resources, and to reproduce video and audio byspecifying such video and audio using such instance (Step S5503). TheJMF 1705 a reproduces the specified video and audio using the set ofresources A2410 or the set of resources B2411 identified by the instanceobtained in Step S5503 (Step S5504).

Fourth Embodiment

In the first to third embodiments, a set of resources is specified byassociating the ServiceContext for Abstract service with aServiceContext for In-band service. The present embodiment, unlike thefirst to third embodiments, is achieved by indicating a set of resourcesdirectly to the ServiceContext for Abstract service. The other part isthe same as the first embodiment, and therefore descriptions are givenin the present embodiment, focusing on how a set of resources and theServiceContext for Abstract service are mapped. FIG. 22 shows aconfiguration of the ServiceContext for In-band service according to thepresent embodiment, whereas FIG. 56 shows the configuration of theServiceContext for Abstract service. The ServiceContext for Abstractservice is comprised of a service execution unit 5611, a resource setspecification unit 5601, and a resource set holding unit 5602. In FIG.56, the service execution unit 5611, upon receipt of a serviceidentifier, obtains a set of resources from the resource set obtainmentunit 2203 of a ServiceContext for In-band service, identifies such setof resources, and executes a service. It is possible for the resourceset specification unit 5601 to associate the ServiceContext for Abstractservice with the set of resources, by specifying such set of resourcesobtained in the resource set obtainment unit 2203. The set of resourcesspecified by the resource set specification unit 5601 are held by theresource set holding unit 5602. FIG. 58 shows an example method ofassociating the ServiceContext for Abstract service with a set ofresources. In FIG. 58, getResourceSet( ) 4411 is newly defined as theresource set obtainment unit 2203 in the ServiceContext for In-bandservice. This method makes it possible to obtain an associated set ofresources. The AbstractServiceContext class 4402 inherits the class ofthe ServiceContext for In-band service, and the resource setspecification unit 5601 newly defines a method. In FIG. 58, a method,setResourceSet(ResourceSet) 4412, is defined as an example. Here, theResourceSet 5801 specified as an augment is a class representing a setof resources. It is possible to specify a set of resources by specifyinga set of resources that is whished to be associated, as an argument ofthis method.

FIG. 60 shows a flowchart in the present embodiment.

A Java program included in an Abstract service obtains a ServiceContextfor In-band service from the ServiceContext obtainment unit of theservice manager 1704 (Step S6001). Then, the Java program obtains aResourceSet from the obtained ServiceContext for In-band service, usinggetResourceSet( ) (Step S6002). Next, using setResourceSet(ResourceSet),the Java program associates the ServiceContext for Abstract service 2108with the ResourceSet 5801 (Step S6003). Then, the Java program requeststhe JMF 1705 a to obtain an instance of a Java class representing a setof resources, and to reproduce video and audio by specifying such videoand audio using such instance (Step S6004). The JMF 1705 a reproducesthe specified video and audio using the set of resources A2410 or theset of resources B2411 identified by the instance obtained in Step S6003(Step S6005).

Here, a detailed flowchart of Step S6004 is shown in FIG. 59. First, theservice execution unit 5611 requests the JMF 1705 a to obtain aninstance of a Java class that represents resources required forreproducing video and audio (the TS decoder A505 a, the audio decoder506 a, and the video decoder 508 a) (Step S5901). The JMF 1705 aspecifies the invoker of the instance of the Java class representing theresources required for reproducing video and audio by a thread, forexample (Step S5902). Here, it is possible for a thread to identify aJava program according to a group to which such thread belongs. And itis possible to obtain the service from such Java program, and obtain theServiceContext A2106 as well as the ResourceSet and the set of resourcesafter making an enquiry to the service manager 1704 (Step S5903). TheJMF 1705 a returns an instance of a Java class representing a set ofresources for reproducing video and audio that are included in the setof resources 2410 obtained in Step S903 (Step S5904). The serviceexecution unit 2201 requests the JMF 1705 a to reproduce video and audiousing the instance obtained in Step S5904 (Step S5905). In other words,the JMF 1705 a functions as a resource management unit that obtains theset of resources (information including resource set information)associated with the ServiceContext A2106, and provides such obtainedresource set information to the service.

Fifth Embodiment

In the present embodiment, unlike the first to third embodiments,resources to be used are specified by directly indicating a set ofresources to the ServiceContext for Abstract service. The other part isthe same as the first embodiment, and therefore descriptions are givenin the present embodiment, focusing on how a set of resources and theServiceContext for Abstract service are mapped.

The configuration of a ServiceContext for In-band service according tothe present embodiment is as shown in FIG. 22, and therefore adescription of it is omitted.

FIG. 57 is a diagram showing the configuration of the ServiceContext forAbstract service (service execution environment). The ServiceContext forAbstract service is comprised of a service execution unit 5701 (serviceexecution unit) and a resource set holding unit 5702. The ServiceContextfor Abstract service and a set of resources (information that includesresource set information indicating one or more resources) areassociated with each other by receiving such set of resources at thesame time of receiving a service identifier in the service executionunit 5701 in the ServiceContext for Abstract service shown in FIG. 57.Furthermore, the received set of resource is held by the resource setholding unit 5702. In other words, since the ServiceContext for Abstractservice 2108 having the resource set holding unit 5702 with the aboveconfiguration is held by the ServiceContext management unit 2001, thisServiceContext management unit 2001 functions as a holding unit thatholds the ServiceContext for Abstract service and the set of resourcesthat are associated with each other.

FIG. 61 shows an example method of associating the ServiceContext forAbstract service and a set of resources. In FIG. 61, a ServiceContextclass 6101 is a ServiceContext for In-band service, anAbstractServiceContext class 6102 is the ServiceContext for Abstractservice, and a ResourceSet Class 5801 is a set of resources.getResourceSet( ) 6111 is newly defined in the ServiceContext class6101, as the resource set obtainment unit 2203. This method makes itpossible to obtain a set of resources in use. The AbstractServiceContextclass 6102 inherits the ServiceContext for In-band service class 6101.The service execution unit 5701 newly has a select(Service, ResourceSet)method 6112. Here, Service and ResourceSet are classes that indicate anAbstract service and a set of resources, respectively. Using thismethod, an Abstract service specified as an argument is executed, andassociated with a ResourceSet specified as an argument, at the sametime. Accordingly, when the Abstract service is executed on theServiceContext for Abstract service, the specified set of resources isused. Furthermore, when a Java program included in the Abstract servicerequires some resources (e.g. reproduction of video and audio), a set ofresources specified as an argument in the select method is to be used.In other words, this select(Service, ResourceSet) method 6112 functionsas an association unit that associates a service execution environmentwith a set of resources.

As described above, in the present invention, since a ServiceContextthat is a service execution environment is associated with a set ofresources, it is possible to control one or more resources as a “set” ofresources at the time of service execution.

FIG. 62 shows a flowchart in the present embodiment. The servicereproduction unit 1702 obtains a ServiceContext for In-band service fromthe ServiceContext obtainment unit of the service manager 1704 (StepS6201). Then, the service reproduction unit 1702 obtains a ResourceSetfrom the obtained ServiceContext for In-band service, usinggetResourceSet( ) (Step S6202). When executing the Abstract service, theservice reproduction unit 1702 specifies a ResorceSet in theselect(Service, ResourceSet) method of the AbstractServiceContext, so asto identify the ResourceSet to be used (Step S6203). In other words, theAbstractServiceContext and the ResourceSet are associated with eachother. Then, the Java program requests the JMF 1705 a to obtain aninstance of a Java class representing the set of resources, and toreproduce video and audio by specifying such video and audio using suchinstance (Step S6204). The JMF 1705 a reproduces the specified video andaudio using the set of resources A2410 or the set of resources B2411identified by the ResourceSet that is associated with theAbstractServiceContext in Step S6203 (Step S6205). Here, a detailedflowchart of Step S6204 is as shown in FIG. 59.

Sixth Embodiment

In the present embodiment, unlike the first to third embodiments,resources to be used are specified by directly indicating a set ofresources to the ServiceContext for Abstract service. The other part isthe same as the first embodiment, and therefore descriptions are givenin the present embodiment, focusing on how a set of resources and theServiceContext for Abstract service are mapped.

In the present embodiment, the ServiceContext for Abstract service and aset of resources are mapped in the service manager 1704. FIG. 63 showsthe configuration of the service manager 1704 according to the presentembodiment. In FIG. 63, 6301 is a ServiceContext-resource set mappingunit. The configuration of the ServiceContext-resource set mapping unitis shown in FIG. 64. The ServiceContext-resource set mapping unit 6301is made up of a resource set holding unit 6401, a resource setobtainment unit 6402, and a resource set mapping achievement unit 6403.FIG. 65 shows the resource set holding unit 6401. In FIG. 65, a column6504 describes ServiceContexts for Abstract service or In-band service.A column 6505 describes sets of resources. Each of lines 6501-6503describes a ServiceContext and a set of resources that are associated.

The resource set obtainment unit 6402 obtains a set of resources that isassociated with the ServiceContext for Abstract service or aServiceContext for In-band service. The resource set mapping achievementunit 6403 associates the ServiceContext for Abstract service with theset of resources.

FIG. 66 shows an example method of associating the ServiceContext forAbstract service with a set of resources. In FIG. 66, the resource setholding unit 6401 is represented as a resourceSetMap class 6211. As amethod to implement the resource set obtainment unit 6402,getResourceSet (ServiceContext) 6212 is defined. Also, as a method toimplement the resource set mapping achievement unit 6403, a voidsetResourceSet(AbstractServiceContext, ResourceSet) method 6213 isdefined. getResourceSet (ServiceContext) 6212 obtains, from theResourceMap that represents the resource set holding unit 6401, aResourceSet to which a ServiceContect specified as an argument isassociated. setResourceSet (AbstractServiceContext, ResourceSet) 6213associates the Abstract ServiceContext and ResourceSet that areassociated as arguments, and stores such relationship in theResourceSetMap. Here, the resourceSet 5801 is a class representing a setof resources.

FIG. 67 shows a flowchart in the present embodiment.

A Java program included in an Abstract service obtains a ServiceContextfor In-band service from the ServiceContext obtainment unit of theservice manager 1704 (Step S6701). Next, the Java program obtains aResourceSet by the obtained ServiceContext for In-band service, usinggetResourceSet (ServiceContext) 6212 (Step S6702). Next, the Javaprogram specifies the ResourceSet by use of setResourceSet(AbstractServiceContext, ResourceSet) 6213 in the ResourceSetMap 6201,so as to identify the ResourceSet to be used (Step S6703). In otherwords, the Java program associates the AbstractServiceContext with theResourceSet. Then, the Java program requests the JMF 1705 a to obtain aninstance of a Java class representing the set of resources, and toreproduce video and audio by specifying such video and audio using suchinstance (Step S6704). The JMF 1705 a reproduces the specified video andaudio using the set of resources A2410 or the set of resources B2411identified by the ResourceSet that is associated with theAbstractServiceContext in Step S6703 (Step S6705). Here, a detailedflowchart of Step S6704 is as shown in FIG. 59.

Seventh Embodiment

In the present embodiment, unlike the first to sixth embodiments, bydirectly indicating a resource to the ServiceContext for Abstractservice, a set of resources including such resource is identified. Theother part is the same as the first embodiment, and thereforedescriptions are given in the present embodiment, focusing on how a setof resources and the ServiceContext for Abstract service are mapped.

In the present embodiment, by mapping a ServiceContext and a set ofresources as well as mapping the set of resources and respectiveresources in the service manager 1704, and then by indicating therespective resources to the ServiceContext for Abstract service, the setof resources is automatically indicated to such ServiceContext forAbstract service. FIG. 68 shows the configuration of the service manager1704 according to the present embodiment. In FIG. 68, 6801 is aServiceContext-resource mapping unit. The configuration of theServiceContext-resource mapping unit is shown in FIG. 69. TheServiceContext-resource mapping unit 6801 is made up of a resourceholding unit 6901, the resource set holding unit 6401, a resourceobtainment unit 6902, the resource set obtainment unit 6402, and aresource mapping achievement unit 6903. The resource set obtainment unit6402 and the resource set holding unit 6401 are shown in FIG. 64, andtherefore descriptions thereof are omitted here. FIG. 70 shows anexample of the resource holding unit 6901. A line 7001 describes sets ofresources, a line 7002 describes tuners, a line 7003 describes TSdecoders, a line 7004 describes audio decoders, and a line 7005describes video decoders. Furthermore, a column 7006 describes the setof resources A2410 and resources included in such set of resourcesA2410, whereas a column 7007 describes the set of resources B2411 andresources included in such set of resources B2411.

Note that the resource holding unit 6901 holds the above tuners, TSdecoders, audio decoders, and video decoders as resources, but it ispossible to carry out the present embodiment if the resource holdingunit 6901 has a different configuration.

The resource obtainment unit 6902 obtains resources to which either theServiceContext for Abstract service or a ServiceContext for In-bandservice is associated. The resource mapping achievement unit 6903associates the ServiceContext for Abstract service with the resources.

FIG. 71 shows an example method of associating the ServiceContext forAbstract service with a set of resources.

In FIG. 71, the resource set holding unit 6401 is represented as theresourceSetMap 6211. The resource holding unit 6901 is represented asthe resourceMap 7111. As a method to implement the resource setobtainment unit 6402, getResourceSet (ServiceContext) 6212 is defined.Also, as the resource obtainment unit 6902, agetResource(ServiceContext, String) method 7112 is defined. Furthermore,as a method to implement the resource mapping achievement unit 6903, avoid setResource (AbstractServiceContext, Object) method 7113 isdefined. getResource(ServiceContext, String) 7112 obtains a resourcethat is indicated by String and that is included in the ResourceSet thatis currently used by the ServiceContext specified as an argument, by useof resourceSetMap 6211 and resourceMap 7111. String is specified by thename of a resource, e.g., a character string such as “Tuner”, as aresult of which an Object representing the Tuner A501 a, for example, isreturned as a return value. setResource(AbstractServiceContext, Object)7113 associates the Abstract ServiceContext specified as an argumentwith the ResourceSet that includes the resource represented by theObject specified as an argument, and stores such relationship in theresourceSetMap 6211. Here, the ResourceSet 5801 is a class representinga set of resources.

FIG. 72 shows a flowchart in the present embodiment.

A Java program included in an Abstract service obtains a ServiceContextfor In-band service from the ServiceContext obtainment unit of theservice manager 1704 (Step S7201). Next, the Java program obtains anObject representing a resource wished to be obtained (e.g. an Objectrepresenting a tuner) by the obtained ServiceContext for In-band serviceand the name of such resource, using getResource(ServiceContext, String)(Step S7202). Next, the Java program indicates the Object representingthe resource to the AbstractServiceContext, using thesertResourceSet(AbstractServiceContext, Object) method in theResourceMap, so as to identify a ResourceSet to be used (Step S7203). Inother words, the Java program associates the AbstractServiceContext withthe ResourceSet that includes the resource obtained in Step S7202. Then,the Java program requests the JMF 1705 a to obtain an instance of a Javaclass representing the set of resources, and to reproduce video andaudio by specifying such video and audio using such instance (StepS7204). The JMF 1705 a reproduces the specified video and audio usingthe set of resources A2410 or the set of resources B2411 identified bythe ResourceSet that is associated with the AbstractServiceContext inStep S7203 (Step S7205). Here, a detailed flowchart of Step S7204 is asshown in FIG. 59.

Eighth Embodiment

In the present embodiment, in the first to seventh embodiments, a set ofresources or an Object for identifying a resource is specified from aServiceContext for In-band service, by associating the ServiceContextfor Abstract service with the ServiceContext for In-band service or theset of resources. However, when the ServiceContext for Abstract servicewishes to use two video decoders, for example, it is troublesome toassociate the ServiceContext for Abstract service with a ServiceContextfor In-band service or a set of resources, every time a video decoder isused. FIG. 75 shows an example of using two video decoders. 7501 is apicture of a television commercial. The other elements are omitted sincethey are shown in FIG. 38.

Suppose that the Java library 1705 in FIG. 17 that is referred to in thefirst embodiment is configured as shown in FIG. 73. In FIG. 73, an SFL7301 is a section filter. The SFL 7301 performs section filtering by useof the section filter A1102 a and the section filter B1102 b shown inFIG. 11A and FIG. 11B, and stores the resultant into the primary storageunit 511. A device 7302 controls the display device A520 a and thedisplay device B520 b shown in FIG. 5. A sound 7303 reproduces audio byuse of the audio decoder A0506 a or the audio decoder B506 b. The otherelements are omitted since they are described in FIG. 17.

The above libraries define Java classes that represent physicalresources, or that are capable of specifying resources and executingthem. FIG. 74, which shows a relationship between the respective actualresources and the respective Java classes that represent physicalresources, or that specify resources to execute them. In FIG. 74, Javaclass instances are shown in 7420 and actual resources are shown in7421. A NetworkInterface class 7401 is defined in the DAVICspecification (DAVIC1.4.1 Specification Part9, Complete DAVICSpecifications: hereinafter referred to as DAVIC specification) and isobtained by the class NetworkInterfaceManager that manages instances ofthe NetworkInterface class, using a method public NetworkInterface[ ]getNetworkInterfaces( ) or a method public NetworkInterfacegetNetworkInterface (TransportStream). The NetworkInterface class isdefined as the tuner 1705 a, and the tuner A501 a is internallyidentified. A SectionFilterGroup 7402 is defined in the DAVICspecification and is obtained using a constructor for theSectionFilterGroup. A SectionFilterGroup class, which is defined as theSFL 7301, uses the section filter A7411. A player 7403 is an interface,and its implementation class reproduces video. The player is defined inthe Java Media Framework specification (Java Media Framework API Version1.0 Constants). It is possible to obtain an instance of animplementation class of the player using the following methods of theclass Manager that generates the player: createPlayer(DataSource); andcreatePlayer(MediaLocator) and createPlayer(URL). The player is definedas the JMF 1705 a, and its implementation class is achieved by use ofthe TS decoder 505 a, the audio decoder A506 a, and the video decoderA508 a internally. An HSound 7404 reproduces sound. The HSound class isdefined in HAVi specification (HAVi v1.1 Java L2 APIs, 15 May 2001:hereinafter referred to as HAVi specification), and is obtained using aconstructor for the Hsound class. The HSound class, which is defined asthe sound 7303, uses the audio decoder A506 a. An HGraphicsDevice 7405,an HVideoDevice 7406, and an HBackgroundDevice 7407 are defined in theHAVi specification. It is possible to obtain instances of the respectiveclasses by the following methods of the HScreen class that manages theHGraphics device 7405, the HVideoDevice 7406, and the HBackgroundDevice7407: public HGraphicsDevice[ ] getHVideoDevices( ) public HVideoDevice[] getHVideoDevices( ) and public HBackgroundDevice[ ]getHBackgroundDevice( ) or public HGraphicsDevicegetDefaultHGraphicsDevice( ) public HVideoDevice getDefaultHVideoDevice() and public HBackgroundDevice getDefaultHBackgroundDevice( ). TheHGraphicsDevice 7405, the HVideoDevice 7406, and the HBackgroundDevice7407 are defined as the device 7302, and indicate a graphics deviceA7412, a video device A7413, and a background device A7414,respectively.

Note that in the present embodiment, Java class instances that representor use resources are configured as shown in FIG. 74, but it is possibleto carry out the present embodiment if a different configuration isemployed.

FIG. 76 shows an example of a ServiceContext for In-band service. TheServiceContext for In-band service defines a getResourceSet( ) method7611, and returns a ResourceSet instance. A ResourceSet 7602 representsa set of resources and defines getResource(String) 7612. By specifyingas string a Java class that uses resources, the getResource 7612 returnsan instance that represents a resource included in such set of resourcesor that uses such resource. For example, it is possible to obtain aninstance of the NetworkInterface class by specifying as, getResource(“NetworkInterface”). An argument here is specified as String (characterstring), but anything such as a resource identifier will do as long asit is possible to specify String. Moreover, a getResources( ) method7613 returns all Java class instances that represent resources. Forexample, it returns an instance of the NetworkInterface class 7401, aninstance of the SectionFileGroup class 7402, an instance of the playerclass 7403, an instance of the HSound class 7404, an instance of theHGraphicsDevice class 7405, an instance of the HVideoDevice class 7406,and an instance of the HBackgroundDevice class 7407. The ServiceContextfor Abstract service 2180 can obtain Java instance(s) to whichresource(s) is/are associated and to identify the resource(s) by callinggetResource(String) or getResources( ) of the ServiceContext.

Note that even in the case where one ServiceContext holds pluralResourceSets, it is possible to implement this by defining publicResourceSet[ ] getResourceSet( ) in the ServiceContext 7601.

Note that it is also possible to obtain instances of classesrepresenting resources by defining public Object[ ] getResources( ) andpublic Object getResource(String) in the ServiceContext.

Ninth Embodiment

In the eighth embodiment, it is possible to identify a resource byobtaining an instance of a Java class from a ServiceContext for In-bandservice. However, in the case where the ServiceContext for Abstractservice directly obtains, from the Java library 1705, an instancerepresenting a physical resource or an instance of a Java class thatuses a resource, it is impossible to know that by which ServiceContextfor In-band service such resource included in a set of resources hasbeen identified. In the present embodiment, it is determined whether ornot a resource is included in a set of resources identified by aServiceContext for In-band service by asking the ServiceContext forIn-band service about which instance has been obtained from the Javalibrary. The other part is the same as the first embodiment, andtherefore a description is given in the present embodiment, focusing onhow a resource is identified.

FIG. 77 shows an example of a ServiceContext for In-band service. 7701is a ServiceContext for In-band service. An isContained(Object) method7711 takes an instance of a Java class that represents a physicalresource specified as an argument or that uses such resource, and judgeswhether an instance specified as such argument uses a resource includedin a set of resources identified by that ServiceContext. If it is judgedthat such instance uses a resource identified by the ServiceContext,true is returned, whereas if it is judged that such instance does notuse a resource identified by the ServiceContext, false is returned.Accordingly, it becomes possible to know which set of resources includesa resource specified as an Object argument.

Tenth Embodiment

In the ninth embodiment, it is judged whether an instance of a Javaclass uses a resource included in a set of resources identified by aServiceContext. However, in the case where display devices shown in FIG.5 are represented in an integrated form, and where its constituentelement is only a video device 7801 as shown in FIG. 78, there is apossibility that two ServiceContexts for In-band service have to shareone video device. In such a case, it is necessary to judge whether aresource is shared or not, in addition to judging whether a resource isassociated with a certain ServiceContext. FIG. 79 shows an example of aServiceContext for In-band. In FIG. 79, isShared(Object) 7911 is newlydefined in a ServiceContext class 7901 that represents theServiceContext for In-band service, in addition to the isContainedmethod 7711 shown in FIG. 77. In this method 7911, when twoServiceContexts for In-band service share a resource, e.g. the samevideo device 7801, true is returned, whereas false is returned when theydo not share a resource.

Eleventh Embodiment

In addition to the ninth embodiment, a method for checking whether ornot a physical resource is in use is added. This makes it possible toidentify an available resource. FIG. 80 shows an example of aServiceContext for In-band. In FIG. 80, a ServiceContext class 8001 is aServiceContext for In-band service. In the ServiceContext class 8001, anisUsed(Object) method 8011 returns true if a physical resource used byan instance of a Java class that is passed as an argument is currentlyin use, whereas it returns false if the physical resource is not in use.The isContained(Object) 7711 is omitted since it is shown in FIG. 77.

Note that it is possible to define the combination of the eighthembodiment with any one of the ninth embodiment to the eleventhembodiment at the same time.

Twelfth Embodiment

In the ninth embodiment to the eleventh embodiment, there is apossibility that an instance to which a set of resources required to beused is associated cannot be obtained, when an instance representing aresource or an instance of a class that uses a resource is obtained fromthe Java library 1705. For example, when an instance is generated usinga constructor, or when the Player is obtained, there may be apossibility that only instances that use a specified set of resources,such as instances of the SectionFilterGroup and HSound, can be obtainedall the time. In such a case, it is made possible to change a set ofresources to be associated to another one for their methods, bydefining, for example, a public void connectResource(Object) method in aServiceContext for In-band service. An instance that represents aresource or an instance of a class that uses a resource is specified asan Object argument.

In the present embodiment, a resource is identified by defining a publicvoid connectResource(Object) method in the ServiceContext for In-bandservice, but it is possible to carry out the present embodiment bydefining public void connectResource(ServiceContext, Object) in theServiceContext for Abstract service. Here, a ServiceContext for In-bandservice is specified as ServiceContext as an argument.

Note that it is possible to carry out the present embodiment if aninstance that represents a resource specified as an Object argument oran instance of a class that uses a resource, is restricted to aspecified instance. For example, it is conceivable that, out ofinstances described in the eighth embodiment, an instance of theNetworkInterface class is defined not to be specified as an argument ofa method in the present embodiment, since it is possible to obtain allinstances that are associated with actual resources.

Thirteenth Embodiment

In the eighth embodiment, it is possible to identify a resource byobtaining an instance of a Java class from a ServiceContext for In-bandservice. However, in the case where the ServiceContext for Abstractservice directly obtains, from the Java library 1705, an instance thatrepresents a physical resource or an instance of a Java class that usesa resource, it is impossible to know which ServiceContext for In-bandhas specified a set of resources that includes the above resource.

The present embodiment makes it possible to identify a resource and aset of resources to be used by providing a ServiceContext as an argumentat the time of obtaining an instance that represents a physical resourceor an instance of a Java class that uses a resource. The other part isthe same as the first embodiment, and therefore a description is givenin the present embodiment, focusing on how a resource is identified. Thefollowing methods are defined using the Java library 1705.

When obtaining an instance of the NetworkInterface class, an instance ofthe NetworkInterface class for identifying a physical resource isobtained by adding a method public NetworkInterface[ ]getNetworkInterfaces(ServiceContext) to the classNetwrokInterfaceManager that manages instances of the NetworkInterfaceclass. An instance of the SectionFilterGroup class for identifying aphysical resource is obtained by providing a ServiceContext as anargument in a constructor of the SectionFilterGroup. An instance of thePlayer class for identifying a physical resource is obtained byproviding, as methods of the class Manager that creates the Player, oneof or all of the following methods for providing a ServiceContext as anargument: createPlayer(DataSource, ServiceContext); createPlayer(MediaLocator, ServiceContext); and createPlayer(URL, ServiceContext).Here, DataSource, MediaLocator, and URL specify the location of AVsources to be reproduced.

Physical resources of HGraphicsDevice, HVideoDevice, andHBackgroundDevice are identified by adding the following methods of theHScreen class: public HGraphicsDevice[ ]getHVideoDevices(ServiceContext); public HVideoDevice[ ]getHVideoDevices(ServiceContext); and public HBackgroundDevice[ ]getHBackgroundDevice(ServiceContext), or public HGraphicsDevicegetDefaultHGraphicsDevice (ServiceContext); public HVideoDevicegetDefaultHVideoDevice(ServiceContext); and public HBackgroundDevicegetDefaultHBackgroundDevice (ServiceContext).

Note that ServiceContext is specified as an argument in the presentembodiment, but it is also possible to carry out the present embodimentby defining a class ResourceSet for identifying a set of resources andthen by specifying an identifier indicating such set of resources, suchas by specifying a ResourceSet as an argument.

Note that the present embodiment presents the above-described methods asmeans for obtaining instances that represent the respective resources orinstances of classes that use the resources, but it is possible to carryout the present embodiment without using the above methods, byspecifying, as an argument, a ServiceContext or an instance of theResourceSet class.

As described above, according to the present invention, by beingequipped with the following, it becomes possible to assign a set ofresources to be required for executing video, audio, a program and thelike included in said one or more services that run on the executionenvironment: a service execution unit operable to execute one or moreservices; an execution environment holding unit operable to hold anexecution environment that identifies a set of resources used by each ofsaid one or more services; and an execution environment selection unitoperable to associate each of said one or more services with the set ofresources identified by the execution environment by associating theexecution environment held by the execution environment holding unitwith each of said one or more services.

Furthermore, with the configuration in which the present inventionfurther comprises an execution environment identifier obtainment unitoperable to obtain, from the execution environment holding unit, anexecution environment identifier indicating the execution environment,wherein the execution environment identifier includes a serviceidentifier receiving unit operable to receive a service identifier, itbecomes possible to execute said one or more services, with the set ofresources being assigned.

Also, with the following configuration, it becomes possible to assign aset of resources identified by an arbitrary execution environment as aset of resources to be required for executing video, audio, and aprogram included in said one or more services that run on the executionenvironment: the execution environment holding unit holds a plurality ofexecution environments, the service executing apparatus comprises anexecution environment identifier obtainment unit operable to obtain,from the execution environment holding unit, execution environmentidentifiers indicating the respective execution environments, each ofthe execution environment identifiers includes an execution environmentidentifier receiving unit operable to receive a second executionenvironment identifier, and the execution environment selection unit,when the execution environment identifier receiving unit receives thesecond execution environment identifier, associates a service that runson each of the execution environments indicated by said each of theexecution environment identifiers with a set of resources of anexecution environment indicated by the second execution environmentidentifier.

Moreover, with the following configuration, said one or more servicesthat run on the execution environment can cause the second service torun on an execution environment indicated by the second executionenvironment identifier: said one or more services that run on theexecution environment indicated by the execution environment identifierobtains a second execution environment identifier by the executionenvironment identifier obtainment unit, passes a second service to aservice identifier receiving unit in the second execution environmentidentifier, and causes the second service to run.

Furthermore, with the following configuration, only a limited serviceout of services that run on the execution environment, can cause thesecond service to run on an execution environment indicated by thesecond execution environment identifier: only a limited service, out ofservices that run on the execution environment indicated by theexecution environment identifier, obtains a second execution environmentidentifier by the execution environment identifier obtainment unit,passes a second service to a service receiving unit in the secondexecution environment identifier, and causes the second service to run.

Also, with the following configuration, it becomes possible to assign aset of resources identified by another execution environment as a set ofresources to be required for executing video, audio, and a programincluded in said one or more services that run on the executionenvironment, and therefore to control sets of resources in a flexiblemanner: the service identifier receiving unit also receives theexecution environment identifier at the same time of receiving theservice identifier, and the execution environment selection unit, whenthe service identifier receiving unit receives, together with theservice identifier, a second execution environment identifier obtainedby the execution environment identifier obtainment unit, associates saidone or more services that run on the execution environment indicated bythe execution environment identifier with a set of resources of anexecution environment indicated by the second execution environmentidentifier.

Moreover, with the configuration in which the present invention furthercomprises an execution environment identifier obtainment unit operableto obtain, from the execution environment holding unit, an executionenvironment identifier indicating the execution environment, whereinsaid execution environment identifier has a resource set obtainment unitoperable to obtain the set of resources identified by the executionenvironment indicated by the execution environment identifier, itbecomes possible to obtain a set of resources and to identify a set ofresources inside the apparatus.

Furthermore, with the following configuration, it becomes possible toexplicitly assign said set of resources as a set of resources to berequired for executing video, audio, and a program included in said oneor more services that run on the execution environment, and therefore tocontrol sets of resources in a flexible manner: the executionenvironment holding unit holds a plurality of execution environments,the execution environment identifier has a resource set receiving unitoperable to receive a set of resources that is obtained from theresource set obtainment unit in a second execution environmentidentifier obtained from the execution environment identifier obtainmentunit, and the execution environment selection unit, when the resourceset receiving unit receives the set of resources, associates said one ormore services that run on the execution environment indicated by theexecution environment identifier with the set of resources identifier bysaid execution environment.

Also with the following configuration in which the set of resources hasan individual resource obtainment unit operable to obtain an individualresource, it becomes possible to control individual resources, and toidentify a set of resources so as to execute video, audio, and a programindividually.

Moreover, with the configuration in which the individual resourceobtainment unit obtains all resources included in the set of resources,it becomes possible to identify all resources included in said set ofresources.

Furthermore, with the configuration in which the present inventionfurther comprises an execution environment identifier obtainment unitoperable to obtain, from the execution environment holding unit, anexecution environment identifier indicating the execution environment,wherein the execution environment identifier has a resource obtainmentunit operable to obtain an individual resource included in the set ofresources identified by the execution environment indicated by theexecution environment identifier, it becomes possible to obtainindividual resources included in the set of resources, and to identifythe set of resources so as to execute video, audio, and a programindividually.

Also, with the configuration in which the resource obtainment unitobtains all resources included in the set of resources, it becomespossible to obtain all resources and therefore to identify all theresources included in said set of resources.

Moreover, with the configuration in which the present invention furthercomprises an individual resource obtainment unit operable to obtain anindividual resource included in the set of resources identified by theexecution environment held by the execution environment holding unit, itbecomes possible to obtain individual resources included in sets ofresources of all execution environments, and to identify a set ofresources so as to execute video, audio, and a program individually.

Furthermore, with the configuration in which the present inventionfurther comprises: an execution environment identifier obtainment unitoperable to obtain, from the execution environment holding unit, anexecution environment identifier indicating the execution environment;and a resource judgment unit operable to judge whether or not the set ofresources identified by the execution environment indicated by theexecution environment identifier includes the resource obtained by theindividual resource obtainment unit, it becomes possible to identify aresource included in a specified set of resources by identifying the setof resources that includes individual resources, and therefore toidentify the set of resources so as to execute video, audio, and aprogram individually.

Also, with the configuration in which the present invention furthercomprises a resource sharing judgment unit operable to judge whether theresource obtained by the individual resource obtainment unit is sharedbetween (i) a set of resources identified by an execution environmentindicated by a second execution environment identifier obtained by theexecution environment identifier obtainment unit and (ii) the set ofresources identified by the execution environment indicated by theexecution environment identifier, by being able to judge whether or notan individual resource is shared by plural sets of resources, only aprogram that runs on the execution environment indicated by theexecution environment identifier is allowed to use such resource, whensuch resource is not shared, which makes it possible to execute video,audio, and a program without having any influences on another service.

Moreover, with the following configuration, by being able to judgewhether or not individual resources are currently in use, it becomespossible to execute video, audio, and a program individually by use ofavailable resources: the execution environment indicated by theexecution environment identifier has a resource use judgment unitoperable to judge whether the resource obtained by the individualresource obtainment unit is being used by the execution environmentindicated by the execution environment identifier obtained by theexecution environment identifier obtainment unit.

Furthermore, with the configuration in which the present inventionfurther comprises an execution environment identifier obtainment unitoperable to obtain, from the execution environment holding unit, anexecution environment identifier indicating the execution environment,wherein the execution environment identifier has a resource connectionunit operable to associate the set of resources identified by theexecution environment indicated by the execution environment identifierwith the resource obtained by the individual resource obtainment unit,by including said resource to said set of resources, it becomes possibleto include a resource to a set of resources that is wished to becontrolled.

Also, with the configuration in which the present invention furthercomprises an execution environment identifier obtainment unit operableto obtain, from the execution environment holding unit, an executionenvironment identifier indicating the execution environment, wherein theindividual resource obtainment unit obtains the resource that isincluded in the set of resources identified by the execution environmentindicated by the execution environment identifier, by specifying theexecution environment identifier obtained by the execution environmentidentifier obtainment unit, it becomes possible to execute video, audio,and a program individually, using a resource that is included in the setof resources identified by the execution environment.

Moreover, with the following configuration, it becomes possible toassign a set of resources identified by the execution environmentindicated by the second execution environment identifier, as a set ofresources to be required for executing video, audio, and a programincluded in said one or more services that run on the executionenvironment: the execution environment holding unit holds a plurality ofexecution environments, the service executing apparatus comprises: anexecution environment identifier obtainment unit operable to obtain,from the execution environment holding unit, execution environmentidentifiers indicating the respective execution environments; and anexecution environment association unit operable to associate each of theexecution environment identifiers with a second execution environmentidentifier that is obtained by the execution environment identifierobtainment unit, and the execution environment selection unit, when theexecution environment association unit associates said each of theexecution environment identifiers with the second execution environmentidentifier, associates a service that runs on each of the executionenvironments indicated by said each of the execution environmentidentifiers with a set of resources of an execution environmentindicated by the second execution environment identifier.

Furthermore, with the following configuration, it becomes possible toassign a set of resources identified by the execution environmentindicated by the second execution environment identifier, as a set ofresources to be required for executing video, audio, and a programincluded in said one or more services that run on the executionenvironment: the execution environment holding unit holds a plurality ofexecution environments, the service executing apparatus comprises anexecution environment identifier obtainment unit operable to obtain,from the execution environment holding unit, execution environmentidentifiers indicating the respective execution environments, each ofthe execution environment identifiers includes a resource set obtainmentunit operable to obtain a set of resources identified by each of theexecution environments indicated by said each of the executionenvironment identifiers, the service executing apparatus comprises aresource set association unit operable to associate said each of theexecution environment identifiers with a set of resources obtained froma resource set obtainment unit in a second execution environmentidentifier, and the execution environment selection unit, when theresource set association unit associates said each of the executionenvironment identifiers with the set of resources, associates a servicethat runs on said each of the execution environments indicated by saideach of the execution environment identifiers with the set of resources.

Also, by being embodied as a computer-readable recording medium in whicha program capable of functioning as the following units is stored, itbecomes possible to improve portability: a service execution unitoperable to execute one or more services; an execution environmentholding unit operable to hold an execution environment that identifies aset of resources used by each of said one or more services; and anexecution environment selection unit operable to associate each of saidone or more services with the set of resources identified by theexecution environment by associating the execution environment held bythe execution environment holding unit with each of said one or moreservices.

Although only some exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention.

INDUSTRIAL APPLICABILITY

Being equipped with the following, the service executing apparatusaccording to the present invention is useful for a program included in aservice when it controls a plurality of resource groups such as Picturein Picture and Double Window in a digital broadcasting receiver: aservice execution unit operable to execute one or more services; anexecution environment holding unit operable to hold an executionenvironment that identifies a set of resources used by each of said oneor more services; and an execution environment selection unit operableto associate each of said one or more services with the set of resourcesidentified by the execution environment by associating the executionenvironment held by the execution environment holding unit with each ofsaid one or more services. Furthermore, the present invention isapplicable not only to digital broadcasting receive, but also to usessuch as controlling a plurality of resource groups in an informationdevice, such as personal computer and mobile phone, that is controlledby software.

1. A broadcast receiving terminal including one or more resources, the broadcast receiving terminal comprising: a receiver operable to receive an application; a recording medium; a service executer operable to execute a service that uses said one or more resources in a service execution environment intended for said service; an associater operable to associate the service execution environment with resource set information indicating said one or more resources used by the service, when the application requests the service executer to execute the service; a storager operable to store, into the recording medium, a plurality of service execution environments together with the associated resource set information that are associated by the associater; and a resource manager operable to provide, to a selected service, said one or more resources indicated in the resource set information in the associated service execution environment, in the recording medium, stored by the storager.
 2. A service executing method in a broadcast receiving terminal including one or more resources, the service executing method comprising: receiving an application; associating, with resource set information, a service execution environment for executing a service that uses said one or more resources, when execution of said service is requested by the application, said resource set information indicating said one or more resources used by the service; storing, into a recording medium included in the broadcast receiving terminal, a plurality of service execution environments together with the associated resource set information; providing, to a selected service, said one or more resources indicated in resource set information in the associated service execution environment stored in the recording medium; and executing the selected service in the service execution environment by use of said one or more resources indicated by the resource set information. 